Question

integral of exp(-kt) from 0 to infinity

Answer 1

That indefinite integral,
Use the property (exp(t)) '=exp() t

Answer 2

Sorry I'm using the phone, things not going well lol

Answer 3

Thank you, but I still don't get it?

Answer 4

Actually you have to to use this property (expkt)'=kexp(t)

Answer 5

Thanks, I will try that.

Answer 6

\[\int\limits_{0}^{\infty }e ^{-kt }dt=\frac{ e ^{-kt} }{ -k }|~from~0~\to~\infty =\frac{ -1 }{ k }\frac{ 1 }{ e ^{k t} } |~0~\to~\infty \]
\[=\frac{ -1 }{ k }\left( 0-\frac{ 1 }{ e ^{0} } \right)=\frac{ 1 }{ k }\]

Answer 7

Thank you very much, that is straightforward and clear.

Answer 8

yw