Why Does the Exponential Calculation in My RC Circuit Equation Return 1?

[physics=world]

Homework Statement

I'm trying to use the equation for charging capacitor that's discharging, and I can't get the answer right. On the calculator it keeps showing as 1.

Homework Equations

I(t) = -(1.96) [e^((-9.0*10^(-6)) / (1300)(2.0*10^(-9)))]

The Attempt at a Solution

My problem is that the exponential part keeps coming out as the value 1 when I input it into the calculator. I need help on solving the exponential part.

 

[voko]

Is the equation $$ -1.96 \exp{\frac {-9.0*10^{-6}}{1300*2.0*10^{-9}}} $$ or is it $$ -1.96 \exp({\frac {-9.0*10^{-6}}{1300}2.0*10^{-9}}) $$?

 

[physics=world]

the first one... e^(-t/RC)

 

[voko]

The way you typed it, however, it will be interpreted as #2. You need additional brackets to enforce #1, OR you must use the division operation twice.

 

[physics=world]

oh. thank you for the clarity. it works.