Question

Is sqrt(1 - sin^2 θ) = cos θ true? if so, in which quadrants does angle θ terminate?​

Answer 1

Answer:

  I and IV

Step-by-step explanation:

Since 1-sin(θ)² = cos(θ)², the given equation is equivalent to ...

  √(cos(θ)²) = |cos(θ)| = cos(θ)

This will be true where the cosine is non-negative, in the first and fourth quadrants.