Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Definite Integration

Question:

The integral $\int\limits_0^1 x(1-x)^{n} d x$ is equal to :

Options:

$\frac{1}{(n+2)(n+3)}$

$\frac{1}{(n+1)(n+2)}$

$\frac{1}{n(n+1)}$

$\frac{1}{(n-1)(n-2)}$

Correct Answer:

$\frac{1}{(n+1)(n+2)}$

Explanation:

The correct answer is Option (2) - $\frac{1}{(n+1)(n+2)}$

$I=\int\limits_0^1 x(1-x)^{n} dx$

$=\int\limits_0^1 (1-x)(x)^ndx$

$=\int\limits_0^1x^n-x^{n+1}dx=\left[\frac{x^{n+1}}{n+1}-\frac{x^{n+2}}{n+2}\right]_0^1$

$=\frac{1}{(n+1)(n+2)}$