show that cos2x=1-tan^ 2 x

Solve the equation of the interval (0, 2pi)cosx=sinx I squared both sides to get :cos²x=sin²x Then using tri indentites I came
1. 4 answers
2. asked by Brian
3. 797 views
Use the Pythagorean identity to show that the double angle formula for cosine can be written asa) cos2x = 1 - 2sin^2x b) cos2x =
1. 1 answer
2. asked by Anonymous
3. 1,656 views
Use the identities cos^2 x + sin^2 x =1and cos2x=cos^2 x -sin^2 x to show that cos^4 x -sin^4 x = cos2x Im not sure how, I can
1. 1 answer
2. asked by Anon
3. 562 views
Solve identity,(1-sin2x)/cos2x = cos2x/(1+sin2x) I tried starting from the right side, RS: =(cos²x-sin²x)/(1+2sinxcosx)
1. 3 answers
2. asked by sh
3. 749 views
Find all solutions to the equation in the interval [0, 2pi)cos4x-cos2x=0 So,this is what i've done so far: cos4x-cos2x=0
1. 1 answer
2. asked by Maria
3. 1,642 views
Please help!!!!!!!!!!! Find all solutions to the equation in the interval [0,2π).8. cos2x=cosx 10. 2cos^2x+cosx=cos2x Solve
1. 5 answers
2. asked by Anonymous
3. 842 views
find all solutions of the equation 2sin x cos2x-cos2x=0 over the interval 0<x<=pi
1. 4 answers
2. asked by owo
3. 2,215 views
Prove that cos3x/cosx-cos6x/cos2x=2(cos2x-cos4x)
1. 2 answers
2. asked by Joel
3. 1,170 views
Where do I start to prove this identity:sinx/cosx= 1-cos2x/sin2x please help!! Hint: Fractions are evil. Get rid of them. Well,
1. 0 answers
2. asked by maria
3. 825 views
show that :cos(360*+x)-tan(150*-x)sin(360*-2x)cos(-x)/ sin(90*+x)=cos2x
1. 0 answers
2. asked by Ben
3. 466 views