How Is Current Calculated in a Circuit with Charge Function q(t)?

[JFonseka]

Homework Statement

The total charge that has entered a circuit element is q(t)=2(3 − e$$^{-4t}$$) when t≥0 and
q(t)=0 when t<0. Determine the current in this circuit element for t≥0.

Homework Equations

Differentiation

The Attempt at a Solution

i(t) = 2(4e$$^{-4t}$$) + 3 - e$$^{-4t}$$

i(t) = 7e$$^{-4t}$$ + 3

However the answer says 8e$$^{-4t}$$

What have I done wrong?

 

[JFonseka]

Nvm. Dumb mistake, just realized. Solved.