critical point of graph

i want to find the critical point of the graph


i done that, but have difficulties then
f'(x)=4x^3+3x^2-36x+24
then f'(x)= 0 is critical point, but i don't know how to solve f'(x)=0.........

Quote:

---

Originally Posted by jackopp

i want to find the critical point of the graph


i done that, but have difficulties then
f'(x)=4x^3+3x^2-36x+24
then f'(x)= 0 is critical point, but i don't know how to solve f'(x)=0.........

---

f'(x) = 0 has no rational roots ... you'll need to use technology to approximate them.