Integral Calculus Question 373

Question: $ \int{e^{x}(1+\tan x+{{\tan }^{2}}x)dx=} $

[Karnataka CET 1999]

Options:

A) $ e^{x}\sin x+c $

B) $ e^{x}\cos x+c $

C) $ e^{x}\tan x+c $

D) $ e^{x}\sec x+c $

Show Answer

Answer:

Correct Answer: C

Solution:

$ I=\int{e^{x}(1+\tan x+{{\tan }^{2}}x})dx $
Þ $ \int{e^{x}(1+\tan x+{{\tan }^{2}}x)dx=\int{e^{x}(\tan x+{{\sec }^{2}}x)},dx.} $ $ I=e^{x}\tan x+c $ $ (\because ,\int{e^{x}[f(x)+{f}’(x)]+x=e^{x}f(x)+c}). $