Using quadratic formula with a ^4

Hi,

I have this problem I need to find solutions for:

x^4-17x^2+77=0

I'm stuck on using the quadratic formula since its not in the right form im used to.

I ignored the ^4 and ^2 and did the formula but got something different than the book.

The book had the problem =x^2 not 0 anymore. Why is that?

Re: Using quadratic formula with a ^4

Quote:

Originally Posted by

**minneola24** I have this problem I need to find solutions for:

$\displaystyle x^4-17x^2+77=0$

Can you solve $\displaystyle u^2-17u+77=0~?$

Then let $\displaystyle u=x^2~.$

Re: Using quadratic formula with a ^4