Question

x^4-13x^2+36=0 Please help. :)

Answer 1

hint: let x^2 = X and solve the quadratic

Answer 2

I get as far as u=9 and u=4 but am unsure what to do after that to get the actual answer.

Answer 3

ok u = x^2 i take it
so x^2 = 9 and x^2 = 4
so you now can get 4 values of x

its an equation in x^4 so there will be 4 roots

Answer 4

so 2 roots are sqrt9 , -sqrt9 = -3 and 3

Answer 5

\[\pm3 and \pm2\]

Answer 6

yup

Answer 7

Okay. :)

Answer 8

right