# Help with definate integration problem

1. Jan 26, 2009

### crm08

1. The problem statement, all variables and given/known data

$$\int$$10$$^{t}$$dt t = [1,2]

2. Relevant equations

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

3. 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?

Last edited: Jan 26, 2009
2. Jan 26, 2009

### 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 !

3. Jan 26, 2009

### crm08

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