Can anyone walk me through the steps of solving either of these problems?

Question

1)Determine the percentage of change of f(x)=e^0.9x at x=15 and x=30

2)For the demand function q=150(245-p^2), find E(p) and determine if the demand is elastic or inelastic (or neither) at the price p=7.

Answer 1

1) f(30)/f(15) = e^(0.9*15)= 729,416
Relative to the initial value at x=15,,
[f(30)-f(15)]/f(15) =729,415 which equals 7.29*10^7 %

2) You have not defined the E(p) function