Find all the real zeros of the polynomial
P(x)=x^3 - 3 x^2 - 11 x+ 5 .
Give them as a comma separated list, and give exact answers - no decimals.
The real zeros of P(x) have x=

Question

Find all the real zeros of the polynomial
P(x)=x^3 - 3 x^2 - 11 x+ 5 .
Give them as a comma separated list, and give exact answers - no decimals.
The real zeros of P(x) have x=

anonymous · Answer

you can make a guess first,
try $f(1), f(-1), f(5), f(-5)$ and see if any get you zero

anonymous · Answer

i am pretty sure $f(5)=0$ 
check it

anonymous · Answer

once you get $f(5)=0$ then you know you can factor this beast as 
$$x^3-3x^2-11x+5=(x-5)(something)$$ and you can find the "something" by division
synthetic division is easiest

anonymous · Answer

you know how to do that?

anonymous · Answer

yes i know hot to do the synthetic division. i got the something as x^2+2x-1

anonymous · Answer

Got it thanks!

anonymous · Answer

yw