Get Answers to all your Questions

header-bg qa

Need solution for RD Sharma Maths Class 12 Chapter 19 Definite Integrals Excercise 19.3 Question 3

Answers (1)

Answer:  10

Hint: Break the range of integration like this   \int_{-3}^{-1} f(x) \& \int_{-1}^{3} f(x)

Given:  \int_{-3}^{3}|x+1| d x

Solution:

                \begin{aligned} &I=\int_{-3}^{3}|x+1| d x \\ & \end{aligned}

                f(x)=|x+1|=\left\{\begin{array}{ll} -(x+1), & \text { if }-3 \leq x \leq-1 \\ (x+1), & \text { if }-1 \leq x \leq 3 \end{array}\right\}

                \begin{aligned} &I=\int_{-3}^{-1} f(x) d x+\int_{-1}^{3} f(x) d x \\ & \end{aligned}

                I=\int_{-3}^{-1}-(x+1) d x+\int_{-1}^{3}(x+1) d x

                \begin{aligned} &I=\left[-\left(\frac{x^{2}}{2}+x\right)\right]_{-3}^{-1}+\left[\frac{x^{2}}{2}+x\right]_{-1}^{3} \\ & \end{aligned}                               \quad\left[\because \int x^{n} d x=\frac{x^{n+1}}{n+1}+c\right]

                y=-\left[\frac{(1-9)}{2}+(-1+3)\right]+\frac{(9-1)}{2}+3+1

                \begin{aligned} &=-(-4+2)+(4+4) \\ & \end{aligned}

                =-(-2)+8 \\

                =2+8 \\

                =10

Posted by

infoexpert27

View full answer

Crack CUET with india's "Best Teachers"

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