Question

Does this polynomial have -3 and 2 as zeros?
p(x)=2x^2+2x-12

Answer 1

plug in x = -3 and tell me what you get

Answer 2

6.66

Answer 3

p(x)=2x^2+2x-12

p(-3)=2(-3)^2+2(-3)-12

p(-3)=2(9)+2(-3)-12

p(-3)=18-6-12

p(-3)=0

Answer 4

So that proves that x = -3 is one root or zero

Answer 5

What about p(x)=x^2-x-6?

Answer 6

same idea: plug in the possible roots one at a time

if you get 0, then it's confirmed to be a root

Answer 7

I got 6...

Answer 8

what are the potential roots you want to test?

Answer 9

The same ones

Answer 10

-3 & 2

Answer 11

ok

Answer 12

testing x = -3

p(x)=x^2-x-6

p(-3)=(-3)^2-(-3)-6

p(-3)=(9)-(-3)-6

p(-3)=9+3-6

p(-3)=6

Answer 13

so x = -3 is NOT a root of p(x)=x^2-x-6

Answer 14

testing x = 2

p(x)=x^2-x-6

p(2)=(2)^2-2-6

p(2)=4-2-6

p(2)=-4


and neither is x = 2

Answer 15

Ok, thank you for explaining it! :)

Answer 16

yw