Find Exponential Equation from data points

[Ocasta]

Hi guys I'm helping my girlfriend with her Calc 1 homework and we seem to be stuck on this one problem. Am I missing something obvious?

Homework Statement

Homework Equations

<br /> P = P_0 a^t<br />

<br /> \frac{5}{20} = \frac{P_0 a^1}{P_0 a^{-1}}<br />

<br /> \frac{1}{4} = a^2<br />

<br /> a = \frac{1}{2}<br />

<br /> 5 = P_0 (1/2)^1<br />

<br /> P_0 = 10<br />

<br /> P(t) = 10 (1/2)^t<br />

 

[Ocasta]

... and a few seconds after I posted this, I realized that we're using the wrong variable. X instead of t, and it works.

Rage! Rage factorial