Question

x^3=3x^2+16 and i'm looking for x :)

Answer 1

x^3=3x^2+16
x^3-3x^2-16=0

Answer 2

Now factor the above cubic polynomial..

Answer 3

can u?

Answer 4

not at all, can you do this ?

Answer 5

x^3=3x^2+16
x^3-3x^2-16=0
x^3-4x^2+x^2-4x+4x-16=0
x^2(x-4)+x(x-4)+4(x-4)=0
(x-4)(x^2+x+4)=0

Answer 6

Can u continue from here?

Answer 7

from (x^2+x+4) is only delta?

Answer 8

ok, but delta <0, so x=4, right?

Answer 9

Yep..... x=4 is the only real solution.

Answer 10

thank you very much :)

Answer 11

WELCOME

Answer 12

:)