Definite Integration Question 47

Question: Suppose f is such that $ f(-x)=-f(x) $ for every real x and $ \int _{0}^{1}{f(x)dx=5,} $ then $ \int _{-1}^{0}{f(t)dt=} $

[MP PET 2000]

Options:

A) 10

B) 5

C) 0

D) - 5

Show Answer

Answer:

Correct Answer: D

Solution:

Given $ f(-x)=-f(x) $

We know that, $ \int _{-a}^{a}{f(x)dx=0=\int _{-a}^{0}{f(x)dx+}\int_0^{a}{f(x)dx}} $

$ \Rightarrow \int _{-1}^{0}{f(x)dx+}\int_0^{1}{f(x)dx=0}\Rightarrow \int _{-1}^{0}{f(x)dx=-5} $

$ \Rightarrow \int _{-1}^{0}{f(t)dt=-5} $ .