Hello, i have a question regarding Integrals of Trig Functions... i'm attaching the equation and my apparantly wrong answer below, any explanation of where i went wrong would be great!

Question

siberman · Answer

$$\int\limits_{\frac{ \pi }{ 2 }}^{\frac{ 3\pi }{ 2 }} \sin \theta  d \theta = \left(-\cos \frac{ 3\pi }{ 2 } \right) - \left(-\cos \frac{ \pi }{ 2 } \right) = 0 - 0 = 0$$

anonymous · Answer

i think your answer is correct because it is a definite integral and not an area of surface

siberman · Answer

@ mikoza I agree!! I assume 'are of surface' is the same as 'magnitude of area', which the question didn't ask for! Time to email my tutor. Thanks!