Find all real zeros of the function y=x^3 - 4 x^2 - 9 x +36.
Give your answer as a comma separated list. If there are no real zeros, type none .
The real zeros are x=

Question

Find all real zeros of the function y=x^3 - 4 x^2 - 9 x +36.
Give your answer as a comma separated list. If there are no real zeros, type none .
The real zeros are x=

anonymous · Answer

-3, 3, 4

anonymous · Answer

Thank you!

anonymous · Answer

You are welcome!  I used my graphing calculator to graph the equation.  It has 3 zeros, which is one for each term, x^(n).

anonymous · Answer

do you know how to do it without a calculator?

anonymous · Answer

Yes, for expressions like this you need to try to plug in small whole numbers like 1,2,3,4 etc.
It's a lot of guess work.
In the equation, the coefficients are 1, -4, 9, and 36.  Those are all perfect squares, so you see right away that the square root of these, or combination of the square roots of these may be solutions.  So try -2, 3, 6 too

anonymous · Answer

alright thank you. i will try!