Find all the points of inflection of the function: f(x)=x^3-3x^2-x+7

f'(x) = 3x^2 - 6x - 1

f''(x) = 6x - 6
= 0 for points of inflection
6x = 6
x = 1
then f(1) = 1-3-1+7 = 4

point of inflection is (1,4)