Prove the trig identity

cos(4x)=2-sec^2(2x)/sec^2(2x)

1 answer

cos(4x) = 2-sec^2(2x)/sec^2(2x)
= 2 cos^2(2x) - 1
= cos^2 (2x) - sin^2(2x)

Now.. do you rememember the double angle formula for cos (2y) ?
Let y = 2x
Similar Questions
  1. Trig Identity Prove:cos(x+y)cos(x-y)=cos^2(x)+cos^2(y)-1
    1. answers icon 1 answer
  2. Prove the trig identitycos(4x)=2-sec^2(2x)/sec^2(2x)
    1. answers icon 0 answers
  3. prove the trig identitycos(4x) = 2-sec^2(2x)/sec^2(2x)
    1. answers icon 1 answer
    1. answers icon 1 answer
more similar questions