Help with definate integration problem

[crm08]

Homework Statement

\int10^{t}dt t = [1,2]

Homework Equations

I know that \int(a^{x})dx = \frac{(a^x)}{ln(x)} + C and x\neq 1

The Attempt at a Solution

I could do this problem as indefinate, but since the restraints include a "1", I can't plug it into the the integral because it will result in a "0" being in the denominator. The answer in the back of the book shows:

\frac{90}{ln(10)}

Should I be using a substitution rule somewhere?

 

[Gib Z]

Well, the equation in your section 2 is actually incorrect, the x and a's should be switched around ( or the dx replaced with da). That solves the problem !

 

[crm08]

sorry never mind, its supposed to be the ln(a) not x