Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Definite Integration

Question:

The area bounded by the curve y = (x –1) (x – 2) (x – 3) lying between the ordinates x = 0 and x = 3 is

Options:

$\frac{7}{4}$ sq. units

4 sq. units

$\frac{11}{4}$ sq. units

3 sq. units

Correct Answer:

$\frac{11}{4}$ sq. units

Explanation:

Reqd. area $=\int\limits_0^3|y| d x=\int\limits_0^1|y| d x+\int\limits_1^2|y| d x+\int\limits_2^3|y| d x$

$=-\left(\frac{x^4}{4}-2 x^3+\frac{11}{2} x^2-6 x\right)_0^1+\left(\frac{x^4}{4}-2 x^3+\frac{11}{2} x^2-6 x\right)_1^2-\left(\frac{x^4}{4}-2 x^3+\frac{11}{2} x^2-6 x\right)_2^3$

$=\frac{9}{4}+\frac{1}{4}+\frac{1}{4}=\frac{11}{4}$ sq units.