Question

Find all the zeros of the equation -3x^4+27x^2+1200=0
Stuck-- all I know is that there are 4 zeros... I think.

Answer 1

-3(x-5)(x^2+16)(x+5)
Start with that

Answer 2

What do I do?

Answer 3

How did you get to that?

Answer 4

ok so the zeros are what you can add to each number in the parenthesis to give you zero, so for example your first zero is 5, because 5-5=0

Answer 5

so +/- 5 and +/- 4

Answer 6

your zeroes are 5, -5, 4i, -4i

Answer 7

How did you get i?

Answer 8

And how did you get the very first equation you wrote?

Answer 9

well do you know how to factor?

Answer 10

Yes.

Answer 11

I just factored out your original equation, once you factor out the equation your result is-3(x-5)(x^2+16)(x+5

Answer 12

Where did the 1200 go?

Answer 13

-3*-5*16*5 = 1200

Answer 14

Ooookay. I am apparently worse at this than I thought!
Thank you.