What are the zeros of f(x)=x^4-7x^3+15x^2-9x

Question

alexwee123 · Answer

well one zero is x =0 :D

anonymous · Answer

zero, one, and a double root at 3

anonymous · Answer

so f(x)= x(x-1)(x-3)^2

anonymous · Answer

do you know how to factor it out yourself though?

anonymous · Answer

no

anonymous · Answer

$$f(x)=x^4-7x^3+15x^2-9x=x(x^3-7x^2+15x-9)$$ but after that i am stuck because i don't know how to solve a cubic equation

anonymous · Answer

possible rational zeros are $\pm1,\pm3,\pm9$ but no one says the zeros are rational, so no i do not know how to factor it unless it was cooked up by some math teacher to make the zeros easy to find, which is what you have to do, check the easy ones

anonymous · Answer

however, one thing i am very good at is cheating, so here is the answer as written by saljudie http://www.wolframalpha.com/input/?i=0%3Dx^4-7x^3%2B15x^2-9x