f(x) = x^3 - 13x^2 + 55x - 75 , find the gradient of the tangent at x=3
f(x) = yy= x3 - 13x2 + 55x - 751) find f'(x) [=dy/dx] Differentiation is (1) multiplying the coefficient by the original power --> 2) reducing the original power by 1dy/dx = 3x2 - 26x + 55
2) find f'(3).f'(3) = 3(3)2 - 26(3) + 55f'(3) = 27 - 78 +55f'(3) = 4Tangent ~ y= [4]x +c
