Definite Integration Question 57

Question: Area bounded by the curve $ y=\sin x $ between $ x=0 $ and $ x=2\pi $ is

Options:

A) 2 sq. unit

B) 4 sq. unit

C) 8 sq. unit

D) None of these

Show Answer

Answer:

Correct Answer: B

Solution:

We have $ y=\sin x $ $ x $ 0 $ \pi /6 $

$ \pi /2 $

$ \pi $

$ 3\pi /2 $

$ 2\pi $ $ y $ 0 0.5 1 0 -1 0 Join these points with a free hand to obtain a rough sketch Required area = (area of $ OAB $ ) + (area of $ BCD) $

= $ \int_0^{\pi }{ydx+\int _{\pi }^{2\pi }{(-y)dx}} $ , ( $ \because $ Area $ BCD $ is below $ x- $ axis) = $ \int_0^{\pi }{\sin xdx-\int _{\pi }^{2\pi }{\sin xdx=4}} $ sq. unit.