Area of a curve revolved about x-axis

[nweis84]

I'm pretty sure I'm setting this up right i just get stuck when i need to integrate it

the equation is y=e^x and rotated around the x-axis

I've attached the question

can someone help me thanks

 

[quantumdude]

You'll need 2 substitutions. The most obvious first substitution would be to let $u=e^x$. Follow that up with an appropriate trig substitution and you're home free.