🏼 https://integralsforyou.com - Integral of 1/(1+cos^2(x)) - How to integrate it step by step using the substitution method!🙈 𝐒𝐚𝐦𝐞 𝐢𝐧𝐭𝐞𝐠𝐫𝐚𝐥, ?...Jan 3, 2017 · sin^2x. Rewrite sec^2x as 1/cos^2x by the identity secx = 1/cosx. =cos^2x(1/cos^2x- 1) = 1 - cos^2x Use the identity sin^2x + cos^2x = 1 solved for sin^2x to get: = sin^2x Hopefully this helps! subtract 1 from both sides. tan2x+1 −1 = sec2x −1. ⇒ sec2x −1 = tan2x. Answer link.Simplify and combine like terms. Tap for more steps... 1−2cos(2x)+cos2(2x) 1 - 2 cos ( 2 x) + cos 2 ( 2 x)This simplifies to sinx. Use sin^2theta + cos^2theta = 1 -> sin^2theta = 1- cos^2theta and csctheta = 1/sintheta. =(sin^2x)(cscx) = (sin^2x)(1/sinx) = sinx Hopefully this helps!Develop the left side: #LS = (cos^2 x)/(sin^2 x) - cos ^2 x = ((cos^2 x)(1 - sin^2 x))/(sin^2 x) =# #= (cos^2 x.cos^2 x)/(sin^2 x) = cot^2 x.cos^2 x# Proved.We would like to show you a description here but the site won’t allow us.Mar 20, 2016 · Explanation: Manipulating the left side using Double angle formulae. ∙ sin2x = 2sinxcosx. ∙ cos2x = cos2x − sin2x. and using sin2x +cos2x = 1 we can also obtain. cos2x = (1 − sin2x) − sin2x = 1 −2sin2x. and cos2x = cos2x −(1 − cos2x) = 2cos2x − 1. ⇒ sin2x 1 +cos2x = 2sinxcosx 1 + 2cos2x − 1 = 2sinxcosx 2cos2x. = 2 sinxcosx ... Sep 13, 2016 · cos x Use trig identity: cos 2a = 2cos^2 a - 1 We get: 2cos^2 (x/2) - 1 = cos x. Trigonometry . Science Anatomy & Physiology Astronomy ... x^{2}-x-6=0-x+3\gt 2x+1; line\:(1,\:2),\:(3,\:1) f(x)=x^3; prove\:\tan^2(x)-\sin^2(x)=\tan^2(x)\sin^2(x) \frac{d}{dx}(\frac{3x+9}{2-x}) (\sin^2(\theta))' \sin(120) \lim _{x\to 0}(x\ln (x)) \int e^x\cos (x)dx \int_{0}^{\pi}\sin(x)dx \sum_{n=0}^{\infty}\frac{3}{2^n} Show More 🏼 https://integralsforyou.com - Integral of 1/(1+cos^2(x)) - How to integrate it step by step using the substitution method!🙈 𝐒𝐚𝐦𝐞 𝐢𝐧𝐭𝐞𝐠𝐫𝐚𝐥, ?...Precalculus. Solve for ? cos (2x)=1. cos (2x) = 1 cos ( 2 x) = 1. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. 2x = arccos(1) 2 x = arccos ( 1) Simplify the right side. Tap for more steps... 2x = 0 2 x = 0. Divide each term in 2x = 0 2 x = 0 by 2 2 and simplify. Aug 16, 2016 · If n > 1 is a positive integer, then: cos^n x = (cos x)^n This is a convenience of notation, to avoid having to use parentheses to distinguish, for example: (cos x)^2 and cos (x^2) By convention we can write: cos^2 x and cos x^2 respectively, without ambiguity. However, in the case of -1, we have a clash of notation. In trigonometry formulas, we will learn all the basic formulas based on trigonometry ratios (sin,cos, tan) and identities as per Class 10, 11 and 12 syllabi. Also, find the downloadable PDF of trigonometric formulas at BYJU'S.Mar 1, 2016 · Using Double angle formula. ∙ cos2x = cos2x − sin2x. and the identity cos2x = 1 − sin2x. ⇒ cos2x = cos2x − sin2x = (1 − sin2x) − sin2x. = 1 − 2sin2x = right hand side. hence proved. Answer link. Now, that we have derived cos2x = cos 2 x - sin 2 x, we will derive cos2x in terms of tan x. We will use a few trigonometric identities and trigonometric formulas such as cos2x = cos 2 x - sin 2 x, cos 2 x + sin 2 x = 1, and tan x = sin x/ cos x.We would like to show you a description here but the site won’t allow us. Trigonometry. Simplify square root of 1-cos (x)^2. √1 − cos2 (x) 1 - cos 2 ( x) Apply pythagorean identity. √sin2(x) sin 2 ( x) Pull terms out from under the radical, assuming positive real numbers. Explanation: One way to simplify this is to use the identity. sin2x +cos2x = 1. From this we can see that. sin2x = 1 − cos2x. Therefore we have. cos2x 1 − cos2x = cos2x sin2x = cot2x. Answer link.Precalculus. Solve for ? cos (2x)=1. cos (2x) = 1 cos ( 2 x) = 1. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. 2x = arccos(1) 2 x = arccos ( 1) Simplify the right side. Tap for more steps... 2x = 0 2 x = 0. Divide each term in 2x = 0 2 x = 0 by 2 2 and simplify. 1 + cos. 2x = 2cos 2 x. 1 – cos2x = 2sin² x. The cos 2 x formula is essentially used to resolve the integration problems. It will be used as. cos 2 x = (cos2x + 1)/2. If you want to solve the integral of (1 – cos 2 x) and (1 + cos 2 x). Both mathematical terms will be calculated with the help of trigonometric identities. We have cos 2 x= 1 ...Aug 16, 2016 · If n > 1 is a positive integer, then: cos^n x = (cos x)^n This is a convenience of notation, to avoid having to use parentheses to distinguish, for example: (cos x)^2 and cos (x^2) By convention we can write: cos^2 x and cos x^2 respectively, without ambiguity. However, in the case of -1, we have a clash of notation. Feb 15, 2021 · 1. verified. Simplify the first trigonometric expression by writing the simplified form in terms of the second expression. 1. 1/1-cos (x) - cos (x)/1+cos (x) ; csc (x) 2. 1/sin (x) cos (x) - cot (x) ; cot (x) 3. cos (x)/1+sin (x) + tan (x) ; cos (x) 4. tan (x) +cot (x)/sec (x) ; sin (x) verified. Prove this identity is true using trigonometric ... A. Công thức cos2x. B. Hàm số y = cos2x. Tập xác định của hàm số y = cos2x. Tập giá trị của y = cos2x. Tính chẵn lẻ của hàm số y = cos2x. Chu kì tuần hoàn của hàm số y = cos2x. C. Đồ thị hàm số y = cos2x. D. Đạo hàm cos2x. E. Nguyên hàm cos2x. Free Pre-Algebra, Algebra, Trigonometry, Calculus, Geometry, Statistics and Chemistry calculators step-by-step 1. I'm being asked to find the arc length of y = sin(x) y = sin ( x) for [0, π 2] [ 0, π 2] using M8 M 8. I've determined that y′2 =cos2 x y ′ 2 = cos 2 x. So, using the formula for arc length, I get 1 +cos2 x− −−−−−−−√ 1 + cos 2 x as my function. Now, they want me to evaluate this using M8 M 8, so I end up with 8 8 ...simplify\:\tan^4(x)+2\tan^2(x)+1; simplify\:\tan^2(x)\cos^2(x)+\cot^2(x)\sin^2(x) Show More; Description. Simplify trigonometric expressions to their simplest form ... 1 + cos. 2x = 2cos 2 x. 1 – cos2x = 2sin² x. The cos 2 x formula is essentially used to resolve the integration problems. It will be used as. cos 2 x = (cos2x + 1)/2. If you want to solve the integral of (1 – cos 2 x) and (1 + cos 2 x). Both mathematical terms will be calculated with the help of trigonometric identities. We have cos 2 x= 1 ...Explanation: 1 cos2x − 1 = 1 − cos2x cos2x = sin2x cos2x = tan2x. Answer link.Apr 12, 2016 · #color(blue)(1-cos^2x)# This expression should look familiar. It is derived from the Pythagorean Identity. #sin^2x+cos^2x=1# where we can subtract #cos^2x# from both sides to get what we have in blue above: #sin^2x=color(blue)(1-cos^2x)# Thus, this expression is equal to. #sin^2x# Feb 15, 2021 · 1. verified. Simplify the first trigonometric expression by writing the simplified form in terms of the second expression. 1. 1/1-cos (x) - cos (x)/1+cos (x) ; csc (x) 2. 1/sin (x) cos (x) - cot (x) ; cot (x) 3. cos (x)/1+sin (x) + tan (x) ; cos (x) 4. tan (x) +cot (x)/sec (x) ; sin (x) verified. Prove this identity is true using trigonometric ... simplify\:\tan^4(x)+2\tan^2(x)+1; simplify\:\tan^2(x)\cos^2(x)+\cot^2(x)\sin^2(x) Show More; Description. Simplify trigonometric expressions to their simplest form ... Here are a few examples I have prepared: a) Simplify: tanx cscx ×secx. Apply the quotient identity tanθ = sinθ cosθ and the reciprocal identities cscθ = 1 sinθ and secθ = 1 cosθ. = sinx cosx 1 sinx × 1 cosx. = sinx cosx × sinx 1 × 1 cosx. = sin2x cos2x. Reapplying the quotient identity, in reverse form: = tan2x. b) Simplify: cscβ ... Feb 17, 2016 · x_1=pi/4 and x_2=(3pi)/4 First, take the half over to the other side to get: cos^2(x) =1/2 then square root: cos(x)=1/sqrt(2). We now need to find the inverse of this. If we look at the graph of cos(x) over the given region we see: graph{cos(x) [-0.1,6.15,-1.2,1.2]} We should expect two answers. 1/sqrt(2) is the exact value for cos(pi/4) So we know at least x_1 = cos^-1(1/sqrt2) ->x_1=pi/4 ... From Pythagoras theorem we get: sin2x +cos2x = 1. So: sin2x = 1 − cos2x = (1 − cosx)(1 + cosx) Answer link.cos^2 x + sin^2 x = 1. sin x/cos x = tan x. You want to simplify an equation down so you can use one of the trig identities to simplify your answer even more. some other identities (you will learn later) include -. cos x/sin x = cot x. 1 + tan^2 x = sec^2 x. 1 + cot^2 x = csc^2 x. hope this helped! Introduction to Trigonometric Identities and Equations; 7.1 Solving Trigonometric Equations with Identities; 7.2 Sum and Difference Identities; 7.3 Double-Angle, Half-Angle, and Reduction Formulas Compute answers using Wolfram's breakthrough technology & knowledgebase, relied on by millions of students & professionals. For math, science, nutrition, history ...sin^2x + cos^2x = 1 the identity known is sin^2x + cos^2x = 1. this can be rearranged to give 1 - cos^2x = sin^2x. using the 'difference of two squares' identity ...View Solution. Evaluate the following integrals: ∫e2x( 1+ sin2x 1+cos2x)dx. 01:41. View Solution. निम्नलिखित समाकलों के मान ज्ञात कीजिए-. ∫ 1 1 +cos2x dx. 02:03. View Solution.This simplifies to sinx. Use sin^2theta + cos^2theta = 1 -> sin^2theta = 1- cos^2theta and csctheta = 1/sintheta. =(sin^2x)(cscx) = (sin^2x)(1/sinx) = sinx Hopefully this helps!A. Công thức cos2x. B. Hàm số y = cos2x. Tập xác định của hàm số y = cos2x. Tập giá trị của y = cos2x. Tính chẵn lẻ của hàm số y = cos2x. Chu kì tuần hoàn của hàm số y = cos2x. C. Đồ thị hàm số y = cos2x. D. Đạo hàm cos2x. E. Nguyên hàm cos2x.Introduction to Trigonometric Identities and Equations; 7.1 Solving Trigonometric Equations with Identities; 7.2 Sum and Difference Identities; 7.3 Double-Angle, Half-Angle, and Reduction FormulasIf n > 1 is a positive integer, then: cos^n x = (cos x)^n This is a convenience of notation, to avoid having to use parentheses to distinguish, for example: (cos x)^2 and cos (x^2) By convention we can write: cos^2 x and cos x^2 respectively, without ambiguity. However, in the case of -1, we have a clash of notation.Jan 4, 2017 · 🏼 https://integralsforyou.com - Integral of 1/cos^2(x) - How to integrate it step by step using integration by substitution!🚶 𝐒𝐭𝐞𝐩𝐬00:00 Substitution... The angle in the one plus cos double angle trigonometric identity can be represented by any symbol but it is popularly written in two different forms. ( 1). 1 + cos ( 2 x) = 2 cos 2 x. ( 2). 1 + cos ( 2 A) = 2 cos 2 A. Thus, the one plus cosine of double angle rule can be written in terms of any symbol.Solve your math problems using our free math solver with step-by-step solutions. Our math solver supports basic math, pre-algebra, algebra, trigonometry, calculus and more.Sep 13, 2016 · cos x Use trig identity: cos 2a = 2cos^2 a - 1 We get: 2cos^2 (x/2) - 1 = cos x. Trigonometry . Science Anatomy & Physiology Astronomy ... Here are a few examples I have prepared: a) Simplify: tanx cscx ×secx. Apply the quotient identity tanθ = sinθ cosθ and the reciprocal identities cscθ = 1 sinθ and secθ = 1 cosθ. = sinx cosx 1 sinx × 1 cosx. = sinx cosx × sinx 1 × 1 cosx. = sin2x cos2x. Reapplying the quotient identity, in reverse form: = tan2x. b) Simplify: cscβ ... View Solution. Evaluate the following integrals: ∫e2x( 1+ sin2x 1+cos2x)dx. 01:41. View Solution. निम्नलिखित समाकलों के मान ज्ञात कीजिए-. ∫ 1 1 +cos2x dx. 02:03. View Solution.sin (2x) = 2 sin x cos x. cos (2x) = cos ^2 (x) - sin ^2 (x) = 2 cos ^2 (x) - 1 = 1 - 2 sin ^2 (x) tan (2x) = 2 tan (x) / (1 - tan ^2 (x)) sin ^2 (x) = 1/2 - 1/2 cos (2x) cos ^2 (x) = 1/2 + 1/2 cos (2x) sin x - sin y = 2 sin ( (x - y)/2 ) cos ( (x + y)/2 ) cos x - cos y = -2 sin ( (x - y)/2 ) sin ( (x + y)/2 ) Trig Table of Common Angles. angle.If n > 1 is a positive integer, then: cos^n x = (cos x)^n This is a convenience of notation, to avoid having to use parentheses to distinguish, for example: (cos x)^2 and cos (x^2) By convention we can write: cos^2 x and cos x^2 respectively, without ambiguity. However, in the case of -1, we have a clash of notation.Free math problem solver answers your algebra, geometry, trigonometry, calculus, and statistics homework questions with step-by-step explanations, just like a math tutor.The expression 1 + cos 2x + cos 4x + cos 6x is equivalent to. NCERT Solutions. NCERT Solutions For Class 12. NCERT Solutions For Class 12 PhysicsSolve your math problems using our free math solver with step-by-step solutions. Our math solver supports basic math, pre-algebra, algebra, trigonometry, calculus and more. 今回は\(\displaystyle\int \displaystyle \frac{1}{\cos^2 x} dx\)を積分していきます。置換積分法を使ったテクニックと微分を使って、下記の積分を実施します。 #color(blue)(1-cos^2x)# This expression should look familiar. It is derived from the Pythagorean Identity. #sin^2x+cos^2x=1# where we can subtract #cos^2x# from both sides to get what we have in blue above: #sin^2x=color(blue)(1-cos^2x)# Thus, this expression is equal to. #sin^2x#Compute answers using Wolfram's breakthrough technology & knowledgebase, relied on by millions of students & professionals. For math, science, nutrition, history ... Trigonometry. Simplify square root of 1-cos (x)^2. √1 − cos2 (x) 1 - cos 2 ( x) Apply pythagorean identity. √sin2(x) sin 2 ( x) Pull terms out from under the radical, assuming positive real numbers.Trigonometry. Simplify square root of 1-cos (x)^2. √1 − cos2 (x) 1 - cos 2 ( x) Apply pythagorean identity. √sin2(x) sin 2 ( x) Pull terms out from under the radical, assuming positive real numbers.Solve your math problems using our free math solver with step-by-step solutions. Our math solver supports basic math, pre-algebra, algebra, trigonometry, calculus and more.Solve your math problems using our free math solver with step-by-step solutions. Our math solver supports basic math, pre-algebra, algebra, trigonometry, calculus and more.In this video I will prove cos^2(x)=(1+cos2x)/2. Course Index. What Is The Unit Circle? The Unit Circle and The Angle (Part 1 of 2) The Unit Circle and The Angle ... Mar 12, 2018 · Explanation: 1 cos2x − 1 = 1 − cos2x cos2x = sin2x cos2x = tan2x. Answer link. Feb 15, 2021 · 1. verified. Simplify the first trigonometric expression by writing the simplified form in terms of the second expression. 1. 1/1-cos (x) - cos (x)/1+cos (x) ; csc (x) 2. 1/sin (x) cos (x) - cot (x) ; cot (x) 3. cos (x)/1+sin (x) + tan (x) ; cos (x) 4. tan (x) +cot (x)/sec (x) ; sin (x) verified. Prove this identity is true using trigonometric ... What is the value of 1+cos^2 (x)? - Quora. Something went wrong. Wait a moment and try again.1. I'm being asked to find the arc length of y = sin(x) y = sin ( x) for [0, π 2] [ 0, π 2] using M8 M 8. I've determined that y′2 =cos2 x y ′ 2 = cos 2 x. So, using the formula for arc length, I get 1 +cos2 x− −−−−−−−√ 1 + cos 2 x as my function. Now, they want me to evaluate this using M8 M 8, so I end up with 8 8 ...Jun 25, 2018 · How do you differentiate #1+cos^2(x)#? Calculus Differentiating Trigonometric Functions Derivative Rules for y=cos(x) and y=tan(x) 1 Answer Jim G. Precalculus. Solve for ? cos (2x)=1. cos (2x) = 1 cos ( 2 x) = 1. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. 2x = arccos(1) 2 x = arccos ( 1) Simplify the right side. Tap for more steps... 2x = 0 2 x = 0. Divide each term in 2x = 0 2 x = 0 by 2 2 and simplify.Apr 12, 2016 · #color(blue)(1-cos^2x)# This expression should look familiar. It is derived from the Pythagorean Identity. #sin^2x+cos^2x=1# where we can subtract #cos^2x# from both sides to get what we have in blue above: #sin^2x=color(blue)(1-cos^2x)# Thus, this expression is equal to. #sin^2x# The expression 1 + cos 2x + cos 4x + cos 6x is equivalent to. NCERT Solutions. NCERT Solutions For Class 12. NCERT Solutions For Class 12 Physics 1. I'm being asked to find the arc length of y = sin(x) y = sin ( x) for [0, π 2] [ 0, π 2] using M8 M 8. I've determined that y′2 =cos2 x y ′ 2 = cos 2 x. So, using the formula for arc length, I get 1 +cos2 x− −−−−−−−√ 1 + cos 2 x as my function. Now, they want me to evaluate this using M8 M 8, so I end up with 8 8 ...simplify\:\tan^4(x)+2\tan^2(x)+1; simplify\:\tan^2(x)\cos^2(x)+\cot^2(x)\sin^2(x) Show More; Description. Simplify trigonometric expressions to their simplest form ...1 Answer (s) Available. Find the integration of the expression as per attachment. 1 Answer (s) Available. Integrate whole root of x- alpha/ beta - alpha lower limit =alpha and upper limit = beta. 1 Answer (s) Available.Here are a few examples I have prepared: a) Simplify: tanx cscx ×secx. Apply the quotient identity tanθ = sinθ cosθ and the reciprocal identities cscθ = 1 sinθ and secθ = 1 cosθ. = sinx cosx 1 sinx × 1 cosx. = sinx cosx × sinx 1 × 1 cosx. = sin2x cos2x. Reapplying the quotient identity, in reverse form: = tan2x. b) Simplify: cscβ ...The expression 1 + cos 2x + cos 4x + cos 6x is equivalent to. NCERT Solutions. NCERT Solutions For Class 12. NCERT Solutions For Class 12 PhysicsThe angle in the one plus cos double angle trigonometric identity can be represented by any symbol but it is popularly written in two different forms. ( 1). 1 + cos ( 2 x) = 2 cos 2 x. ( 2). 1 + cos ( 2 A) = 2 cos 2 A. Thus, the one plus cosine of double angle rule can be written in terms of any symbol.We would like to show you a description here but the site won’t allow us.Dec 2, 2018 · In this video, we are going to derive value of 1 - cosine of 2x.The identity cos(2x) has been explained in the following videohttps://youtu.be/NTgX1EY6Poo#co... Free math problem solver answers your algebra, geometry, trigonometry, calculus, and statistics homework questions with step-by-step explanations, just like a math tutor. Explanation for correct option: Find the value of lim x → 2 1 - cos 2 x - 2 x - 2. Consider the given Equation as. I = lim x → 2 1 - cos 2 x - 2 x - 2. We know that. cos 2 θ = 1 - 2 sin 2 θ. Then, on substituting we have, I = lim x → 2 1 - 1 - 2 sin 2 x - 2 x - 2 ⇒ I = lim x → 2 2 sin 2 x - 2 x - 2 ⇒ I = lim x → 2 2 sin x - 2 x ...
How do you differentiate #1+cos^2(x)#? Calculus Differentiating Trigonometric Functions Derivative Rules for y=cos(x) and y=tan(x) 1 Answer Jim G.. Fantasy football 5th pick 10 team league
Hint: cos(2x) = cos(x+x)= cosxcosx−sinxsinx= cos2x−sin2x= cos2x−(1−cos2x)= 2cos2x−1 So, cos2x= 21+cos(2x) which can be substituted. For which a ∈ R are sin2(ax),cos2(x) and 1 linear independent. You have sin2(x)= (1−cos(2x))/2 and cos2(ax) =(1+cos(2ax)/2. Hence the span of the three functions is the same as the span of 1, cos(2ax ...x^{2}-x-6=0-x+3\gt 2x+1; line\:(1,\:2),\:(3,\:1) f(x)=x^3; prove\:\tan^2(x)-\sin^2(x)=\tan^2(x)\sin^2(x) \frac{d}{dx}(\frac{3x+9}{2-x}) (\sin^2(\theta))' \sin(120) \lim _{x\to 0}(x\ln (x)) \int e^x\cos (x)dx \int_{0}^{\pi}\sin(x)dx \sum_{n=0}^{\infty}\frac{3}{2^n} Show MoreFree integral calculator - solve indefinite, definite and multiple integrals with all the steps. Type in any integral to get the solution, steps and graphTeks video. 1 Min Cos 2 X per 1 + cos 2x = sebelum kita kerjakan soal berikut perlu kita ingat kembali bahwa cos 2x kita bisa berubah menjadi 1 min 2 Sin kuadrat X sehingga 1 Min Cos 2 e-paper 1 + cos 2x bisa kita rubah menjadi 1 Min cos 2x nya kita bahas 1 min 2 Sin kuadrat X per 1 + cos 2x ditambah 1 Min Sin kuadrat X kemudian 1 dikurang 1 habis kemudian Min ketemu Min jadinya + 2 SinX per 1 ...You don't have to memorize all formulas but it helps to do so. If you remember, 1 = cos^2 x + sin^2 x. So we have, cos^2 x = 1 - sin^2 x and sin^2 x = 1 - cos^2 x. If we replace cos^2 x in the first double angle formula cos2x = cos^2 x - sin^2 x with 1 - sin^2 x we get: cos2x = 1 - 2 sin^2 x. Free trigonometric identity calculator - verify trigonometric identities step-by-step The expression 1 + cos 2x + cos 4x + cos 6x is equivalent to. NCERT Solutions. NCERT Solutions For Class 12. NCERT Solutions For Class 12 PhysicsJun 26, 2016 · From Pythagoras theorem we get: sin2x +cos2x = 1. So: sin2x = 1 − cos2x = (1 − cosx)(1 + cosx) Answer link. Hint: cos(2x) = cos(x+x)= cosxcosx−sinxsinx= cos2x−sin2x= cos2x−(1−cos2x)= 2cos2x−1 So, cos2x= 21+cos(2x) which can be substituted. For which a ∈ R are sin2(ax),cos2(x) and 1 linear independent. You have sin2(x)= (1−cos(2x))/2 and cos2(ax) =(1+cos(2ax)/2. Hence the span of the three functions is the same as the span of 1, cos(2ax ... Use the identity: cos (a + b) = cos a.cos b - sin a.sin b cos 2x = cos (x + x) = cos x.cos x - sin x. sin x = cos^2 x - sin^2 x = = cos^2 x - (1 - cos^2 x) = 2cos ^2 ...cos^2 x + sin^2 x = 1. sin x/cos x = tan x. You want to simplify an equation down so you can use one of the trig identities to simplify your answer even more. some other identities (you will learn later) include -. cos x/sin x = cot x. 1 + tan^2 x = sec^2 x. 1 + cot^2 x = csc^2 x. hope this helped! Compute answers using Wolfram's breakthrough technology & knowledgebase, relied on by millions of students & professionals. For math, science, nutrition, history ....