Solving Trig Identities

Solve the following for cos²θ:
sin²θ + cos²θ = 1

• cos²θ = 1 - sin²θ

• cosθ = 1 + sin²θ

• cosθ = 1 - sinθ

• cos²θ = Adj/hyp

Choose a good way to start solving this equation

tanx sin²x = 2 tanx

• divide tanx from both sides

• factor out tanx

• subtract 2 tanx from the left and then factor tanx out

• cancel sin²x out

Factor 0 = sin²x − sinx

• 0 = sinx(sinx)

• 0 = sinx(1 − sinx)

• 0 = cosx(sinx − 1)

• 0 = sinx(sinx − 1)

csc²x = 2 is equivalent to sin²x = ½

• True

• False

• (cos/sin)(sin/cos)

• cos

• sin

• (sin/cos)(cos/sin)

Which of the following would be a step to prove the following identity?

• (1/ sin x) - (1 / cos x)

• (cos x - sin x) / ( sin x)

• (cos x - sin x) / (cos x)

• (1/ sin x cos x)

• cot Θ

• cos Θ

• tan^-1 Θ

• csc Θ

• Both A and B

• Neither A nor B

What would be a step to prove the following:

• (1)(1)

• (1/tanx)(tanx/1)

• (sinx/cosx)(cosx/sinx)

• (cosx/sinx)(sinx/cosx)

*

• csc x

• sec x

• cot x

• tan x