Integral Calculus Question 246

Question: $ \int_{{}}^{{}}{x\sqrt{2x+3}}\ dx= $

[AISSE 1985]

Options:

A) $ \frac{x}{3}{{(2x+3)}^{3/2}}-\frac{1}{15}{{(2x+3)}^{5/2}}+c $

B) $ \frac{x}{3}{{(2x+3)}^{3/2}}+\frac{1}{15}{{(2x+3)}^{5/2}}+c $

C) $ \frac{x}{2}{{(2x+3)}^{3/2}}+\frac{1}{6}{{(2x+3)}^{5/2}}+c $

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

$ \int_{{}}^{{}}{x{{(2x+3)}^{1/2}}dx} $
$ =x\frac{{{(2x+3)}^{3/2}}}{3/2}\frac{1}{2}-\int_{{}}^{{}}{\frac{{{(2x+3)}^{3/2}}}{3/2}\frac{1}{2},dx+c} $
$ =\frac{1}{3}x{{(2x+3)}^{3/2}}-\frac{1}{3}\int_{{}}^{{}}{{{(2x+3)}^{3/2}}dx+c} $
$ =\frac{1}{3}x{{(2x+3)}^{3/2}}-\frac{1}{15}{{(2x+3)}^{5/2}}+c. $