The slope of a function at a point is the value of its derivative there.
... f'(x) = 5·(2x) + 0 = 10x . . . . . . using the power rule: (d/dx)(xⁿ) = n·xⁿ⁻¹
Then
... f'(4) = 10·4 = 40 . . . . . the slope at x=4
6.5m questions
8.7m answers