The the function f(x)=x^3-x^2+4x-3, determine

a) the intervals of increase or decrease

b) the location of any maximum or minimum points

c) the intervals of concavity up or down

d)the location of any points of inflection

I have gotten this far

the derivatives are

f'(x) = 3x^2 -2x +4

f''(x)= 6x-2

I cant figure out how to factor the first derivative in order to find the zeros, help anyone?