- #1
paulmdrdo1
- 385
- 0
just want to confirm if i did set up my integral correctly and got a correct answer.
$\displaystyle\int_0^a (e^{\frac{x}{a}}-e^{-\frac{x}{a}})$
using substitution for the first term in my integrand
$\displaystyle u=\frac{x}{a}$ $\displaystyle du=\frac{1}{a}dx$; $\displaystyle dx=adu
$
for the second term of my integrand,
$\displaystyle v=-\frac{x}{a}$; $\displaystyle dv=-\frac{1}{a}dx$; $\displaystyle dx=adv$
my integrand will now be,
$\displaystyle a\int_0^a e^udu+a\int_0^a e^{-v}dv$
$\displaystyle ae^{\frac{x}{a}}+ae^{-\frac{x}{a}}|_0^a$
plugging in limits of integration,
$\displaystyle ae^{\frac{a}{a}}+ae^{-\frac{a}{a}}-(ae^{\frac{0}{a}}+ae^{-\frac{0}{a}})$
simplifying we have,
$\displaystyle ae^1+ae^{-1}-ae^0-ae^{0}=ae+ae^{-1}-2a=a(e+\frac{1}{e}-2)$
please kindly check if i have any errors. thanks!
$\displaystyle\int_0^a (e^{\frac{x}{a}}-e^{-\frac{x}{a}})$
using substitution for the first term in my integrand
$\displaystyle u=\frac{x}{a}$ $\displaystyle du=\frac{1}{a}dx$; $\displaystyle dx=adu
$
for the second term of my integrand,
$\displaystyle v=-\frac{x}{a}$; $\displaystyle dv=-\frac{1}{a}dx$; $\displaystyle dx=adv$
my integrand will now be,
$\displaystyle a\int_0^a e^udu+a\int_0^a e^{-v}dv$
$\displaystyle ae^{\frac{x}{a}}+ae^{-\frac{x}{a}}|_0^a$
plugging in limits of integration,
$\displaystyle ae^{\frac{a}{a}}+ae^{-\frac{a}{a}}-(ae^{\frac{0}{a}}+ae^{-\frac{0}{a}})$
simplifying we have,
$\displaystyle ae^1+ae^{-1}-ae^0-ae^{0}=ae+ae^{-1}-2a=a(e+\frac{1}{e}-2)$
please kindly check if i have any errors. thanks!