
William W. answered 09/06/20
Experienced Tutor and Retired Engineer
Using the power rule, the derivative of h(x) = 4 − 3x3, is h'(x) = -9x2 so h'(1) = -9 meaning the slope of the tangent line at (1, 1) is -9. That means the equation of the tangent line, using the point, slope form of a line is:
y - 1 = -9(x - 1)
y - 1 = -9x + 9
y = -9x + 10 so m = -9 and b = 10