Question

How do you use the derivative to find the slope of a curve at a point?

Answer 1

If `f'(x)` is the derivative of `f(x)`, input the x value of the point to f'(x).

Say you have `f(x) = x^2`, then the derivative is `f'(x) = 2x`.

To find the slope of `x^2` at the point (3,9), put the x value of the point into the derivative: `f'(3) = 2*3 = 6`.

So at (3,9) the function is sloping upwards at 6 units.