Get Answers to all your Questions

header-bg qa

Explain solution for  RD Sharma Class 12 Chapter 19 Definite Integrals Exercise 19.4 (b) Question 23 maths textbook solution.

Answers (1)

Answer:- 0

Hints:-  You must know the integration rules of trigonometric functions .

Given:-  \int_{-\pi / 2}^{\pi / 2} x \cdot \cos ^{2} x \cdot d x

Solution :  I=\int_{-\pi / 2}^{\pi / 2} x \cdot \cos ^{2} x \cdot d x

                \begin{aligned} &f(x)=x \cdot \cos ^{2} x \\ &f(-x)=(-x) \cos ^{2}(-x) \\ &=-x \cos ^{2} x \\ &=-f(x) \end{aligned}

Hence, f(x) is an odd function.

Since, \int_{-a}^{a} f(x) d x=0, \text { if } f(x) is an odd function

\therefore I = 0

Posted by

infoexpert23

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads