Respuesta :

Correct question is;

Type the correct answer in the box bellow: If cos x = sin(20 + x)° and 0° < x < 90°, the value of x is ...........

Answer:

x = 35°

Step-by-step explanation:

We are told that;

cos x = sin(20 + x)°

and 0° < x < 90°

From trigonometric identities, we know that;

cos x = sin (90 - x)

Applying to our question gives;

sin (90 - x) = sin (20 + x)°

Comparing both sides, we have;

90 - x = 20 + x

Rearranging;

90 - 20 = x + x

70 = 2x

x = 70/2

x = 35°