Absolutely Atrocious

Calculus Level 3

1 1 [ x 2013 e x ( x 2 + cos x ) + 1 e x ] d x = ? \int _{ -1 }^{ 1 }{ \bigg [ \cfrac { { x }^{ 2013 } }{ { e }^{ \left| x \right| }({ x }^{ 2 }+\cos x) } +\cfrac { 1 }{ { e }^{ \left| x \right| } } } \bigg ] dx = \ ?

0 0 1 e 1 1-{ e }^{ -1 } 2 ( 1 e 1 ) 2(1-{ e }^{ -1 }) 2 e 1 2{ e }^{ -1 }

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Deepansh Mathur
Apr 24, 2014

We are aware of the property

\int\limits_{-a}^{a} f(t) \mathrm{d}t = \left\{ \begin{array}{1 1} 0 & \quad \text{if \$f(t)\$ is odd}\\ 2\int\limits_0^{a} f(t) \mathrm{d}t & \quad \text{if \$f(t)\$ is even} \end{array} \right.

Hence we can split the given integrand into two functions. One is odd and one is even.

The integral with odd integrand reduces to 0 0

The integral with even integrand reduces to

2 0 1 1 e x d x \Rightarrow 2\int\limits_0^{1} \frac{1}{e^{|x|}} \mathrm{d}x

2 0 1 e x d x \Rightarrow 2\int\limits_0^{1} e^{-x} \mathrm{d}x

2. [ e x ] 0 1 \Rightarrow -2.[e^{-x}]_0^1

2. ( e 0 e 1 ) \Rightarrow 2.(e^0 - e^{-1})

2 ( 1 e 1 ) \Rightarrow 2(1 - e^{-1})

1 pending report

Vote up reports you agree with

×

Problem Loading...

Note Loading...

Set Loading...