Question

For what value of x is sin x = cos 19°, where 0°< x < 90°?

Answer 1

COsine stands for COMPLEMENTARYsine. The sin of an angle is the cos of its complement, and vice versa.

What's the complement of 19 deg?

Answer 2

71 degree

Answer 3

and if you don't remember, complementary angles mean they sum to 90 degrees