Question

Find all roots of 2x^4 + 7x^3 - 2x^2 - 19x - 12

I got the -3, the touching -1 which means you have to square it, and 1.68, not sure how I solve this.

Answer 1

\[f(x)=2x^4 + 7x^3 - 2x^2 - 19x - 12\]using factor theorem:
f(-1) = 0
f(-3)=...

factor out the known roots
(x+1) &x+3 then deal with the quadratic function left

Answer 2

2x^2 - x - 4 is what i got

Answer 3

now quadratic?

Answer 4

yes

Answer 5

so
1+- sqrt 33 / 4

Answer 6

yes

Answer 7

so
-1,-3, and 1+- sqrt 33 / 4 are my answers?

Answer 8

yes ... when 2x^4 + 7x^3 - 2x^2 - 19x - 12 = 0

Answer 9

Ok thank you! All finished!