y = e2x(x2+1)5/2
The first step is to calculate dy/dx. We can do this by splitting y into two parts and using the chain rule of differentiation:
y = uv
where u = e2x and v = (x2+1)5/2. We now differentiate u and v separately with respect to x.
Here, remember that df(g(x))/dx is equal to df/dg times dg/dx. So,
du/dx = 2e2x and dv/dx = 5/2 (x2+1)3/2 2x = 5x(x2+1)3/2
Using the chain rule,
dy/dx = u dv/dx + v du/dx
= e2x 5x(x2+1)3/2 + 2e2x (x2+1)5/2.
Now, when x=0, the first term disappears, since it's multipled by x. exp(0) is equal to 1, as is 15/2, so the second term reduces to 2 times 1. The answer is therefore 2.