Is this differentiation right.
If I do this how do I find the gradient. If I sub x=0 i don't get what I want.
That is the curve gradient for any x.
If you sub in x=0, you get the slope of the tangent to the curve at x=0,
but not the slope of the tangent that passes through the origin if that's what you were looking for.
What were you trying to calculate ?