Verified answer

pi = 180 degrees so, 90+180 = 270 degrees

sin(270 degrees) = 1

Thanks for the additional details. Instead of pi in the question it should be x.

So, to solve this question, lets use some test cases.

For sin(90 + 0), the value goes from sin(0) = 0 to sin(90) = 1

For sin(90 + 90), the value goes from sin(90) = 1 to sin(180) = 0

Since cos(0) = 1 and cos(90) = 0, the answer is b) cos x

π radians = 180º so it's sin 270º which is -1

assuming the π is in radians; it's a weird question

WHAT DO THEY THINK THEY'RE DOING MIXING RADIANS AND DEGREES!?!?