Prove: cos4x = 8cos^4x -

Prove thatcos4x=8cos^4x-8cos^2x+1 so I'm guessing you begin with the left side cos4x=cos2(2x) then im kinda lost
1. 2 answers
2. asked by Natash
3. 1,286 views
Prove:cos4x = 8cos^4x - 8cos^2x + 1 My Attempt: RS: = 4cos^2x (2cos^2x - 1) + 1 = 4 cos^2x (cos2x) + 1 LS: = cos2(2x) =
1. 38 answers
2. asked by Anonymous
3. 2,744 views
Prove that it is an identity: cos (4x)=8cos^4(x)-8cos^2(x)+1
1. 1 answer
2. asked by Anonymus
3. 2,035 views
Prove cos4x = 8 cos^4x-8 cos^2x+1
1. 1 answer
2. asked by Dini
3. 443 views
sin^4 x = (3-4cos 2x + cos4x)/8prove on one side please!
1. 4 answers
2. asked by Rachel
3. 2,351 views
Prove or disprove the following identity:(sin(10x))/(sin(x)+sin(9x)) = (cos(5x))/(cos4x))
1. 1 answer
2. asked by Natalie
3. 2,491 views
Prove the identity.6cos^2(x)-1 -12cos^4(x) +8cos^6(x)= cos^3(2x) Thanks for your help :)
1. 3 answers
2. asked by Tommy
3. 605 views
please help me on the following:prove the identity. cos4x = 1-8sin^x2cos^2x
1. 0 answers
2. asked by John
3. 437 views
please help me on the following:prove the identity. cos4x = 1-8sin^x2cos^2x
1. 1 answer
2. asked by John
3. 477 views
Prove the identityCos⁴x + sin²x = sin⁴x + cos²x
1. 1 answer
2. 108 views