Prove that cos2x=(1-tan^2x)/(1+tan^2x) I can't

Prove that cos3x/cosx-cos6x/cos2x=2(cos2x-cos4x)
1. 2 answers
2. asked by Joel
3. 1,215 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. 878 views
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. 863 views
prove sin2x+cos2x+1 tan(pi/4+x)______________ = __________ sin2x+cos2x-1 tanx so what I did tan(x)
1. 2 answers
2. asked by Lana
3. 790 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. 807 views
Prove that sin2x+cos2x-1/sin2x+cos2x+1=tanx
1. 1 answer
2. asked by James
3. 1,291 views
prove that1+sin2x-cos2x / sin2x+cos2x = tanx
1. 1 answer
2. asked by Anonymous
3. 1,410 views
Prove that:(tan^2x +1)cos2x=2-sec^2x
1. 2 answers
2. asked by Sandra
3. 1,098 views
Someone please help me prove theseA) cos^4x-sin^4x=cos2x B)tanx=sin^2x/1+cos^2x Please and Thank you
1. 1 answer
2. asked by Bethany
3. 478 views
Someone please help me prove theseA) cos^4x-sin^4x=cos2x B)tanx=sin^2x/1+cos^2x Please and Thank you
1. 1 answer
2. asked by Samantha
3. 560 views