In a roof truss design, two beams are placed such that one makes an angle θ with the horizontal and the other makes (90° - θ). If sin θ = 0.6, what is the value of sin²θ + cos²(90° - θ)?
Show answer & explanation
Correct answer: B
Explanation
Given:
sinθ = 0.6
By the formula:
cos(90° − θ) = sinθ
sin²θ + cos²(90° − θ)
= sin²θ + (sinθ)²
= 2sin²θ
= 2(0.6)²
= 2(0.36)
= 0.72