Using complete sentences, describe how you would verify the zeros of a function.
Use your description to verify the following:
f(x) = x^4 - x^3 + 7x^2 - 9x - 18
positive - 3 or 1
negative - 1
complex - 2 or 0

Question

Using complete sentences, describe how you would verify the zeros of a function. 
Use your description to verify the following: 
f(x) = x^4 - x^3 + 7x^2 - 9x - 18
positive - 3 or 1
negative - 1
complex - 2 or 0

anonymous · Answer

To verify a possible zero (root) to a function, simplify plug in that root and see what you get from the function. If you get zero, then the suspected root is in fact a root.

anonymous · Answer

how do i do that?

anonymous · Answer

Plug in x= the root. Then evaluate the function, and see if you get 0.

anonymous · Answer

can you show me an example?

anonymous · Answer

Sure, to test whether 0 is a root, plug in x=0 and you get:
0^4 - 0^3 +7(0^2) - 9(0) -18
0 - 0 + 0 - 0 - 18
-18

We didn't get zero, so 0 is not a root.

anonymous · Answer

oh okay now i understand a bit more clearly lol

anonymous · Answer

okay so i tired them all and none of them worked...

anonymous · Answer

nvm i miscalculated

anonymous · Answer

I graphed it and found two roots. What did you get?