A particle moves according to the position function x(t)=ct2+bt where c=3m/s2 and b=-7m/s. Find the velocity at the origin.
2. The attempt at a solution
I tried just taking the derivative and setting t=0 to the equation as so:
Although, when I put the answer into WebAssign it says I'm incorrect. I'm not looking for a definite answer since this is my homework but would just like to understand what I am doing wrong.