Question

Trigonometric identities Simplify cos^2 theta -1/ 4 sin^2 theta

Answer 1

B

Explanation:

using the identity

sin²x + cos²x = 1 ( subtract 1 from both sides )

sin²x + cos²x - 1 = 0 ( subtract sin²x from both sides )

cos²x - 1 = - sin²x

then

`(cos^20-1)/(4sin^20)`

=
`(-sin^20)/(4sin^20)` ← cancel sin²Θ on numerator and denominator

=
`(-1)/(4)`

= -
`(1)/(4)`