Integral Calculus Question 463

Question: $ \int_{{}}^{{}}{{e^{x^{2}}}x\ dx} $ is equal to

[SCRA 1996]

Options:

A) $ {e^{x^{2}}} $

B) $ \frac{1}{2}{e^{x^{2}}} $

C) $ 2{e^{x^{2}}} $

D) $ \frac{{e^{x^{2}}}-x^{2}}{2} $

Show Answer

Answer:

Correct Answer: B

Solution:

$ \int_{{}}^{{}}{{e^{x^{2}}}.x,dx}=\frac{1}{2}\int_{{}}^{{}}{(2x){e^{x^{2}}}dx} $ $ =\frac{1}{2}\int_{{}}^{{}}{e^{t}dt}=\frac{1}{2}e^{t}=\frac{1}{2}{e^{x^{2}}} $ , (Put $ x^{2}=t\Rightarrow dt=2x,dx) $ .