Question

Prove that cos^2

θ – sin^2theta

θ = 1 – 2 sin^2theta

θ = 2 cos^2theta

θ – 1

please answer I will mark brainliest​

Answer 1

Answer:

The Pythagorean identity states that

sin^2θ+cos^2θ=1 .

We can rearrange the identity to see that

cos^2θ=1−sin2^θ .

If we know that

cos^2θ=1−sin^2θ , we can replace

cos^2θwith 1−sin2^θ in the expression

cos^2θ−sin^2θ .

cos^2θ−sin^2θ=(1−sin^2θ)−sin^2θ

Combine like terms to see that:

cos^2θ−sin^2θ=1−2sin^2θ.............(1)proved

I would use:

sin^2(θ)+cos^2(θ)=1

and so:

sin^2(θ)=1−cos^2(θ)

in your expression:

cos^2(θ)−1+cos^2(θ)=2cos^2(θ)−1

and:

2cos^2(θ)−1=2cos^2(θ)−1.......(2)prove

Answer 2

Answer:

you know that b_f stands for

both best f_r_ie_n_d and bo_y

fr_i_e_n_d