Question

What value of θ makes cosθ = sin40° a true statement?
A) 20°
B) 40°
C) 50°
D) 90°

HINT: Complementary angles

Answer 1

Answer:

C) 50°

Step-by-step explanation:

$cos \: \theta = sin \: 40 \degree \\ cos \: \theta = cos(90 \degree - \: 40 \degree) \\ cos \: \theta = cos \: 50 \degree \\ \implies \: \theta = 50 \degree$