Question

if cos(40 + ) = 30, find the value of x

Answer 1

Answer:

x = 20°

Step-by-step explanation:

i think so this is the correct question, cos(40°+x) = sin30°

As we know,

sin(90°-α) = cosα

∴sin30° = sin(90°-60°)

            =cos60°

∵cos(40°+x) = sin30°

⇒cos(40°+x) = cos60°

⇒40°+x = 60°

⇒x = 20°