Question

How would you solve x^4=2x^2-1? Precalculus prerequisites

Answer 1

Start by factoring it.

Answer 2

I believe so, it says solve the equation algebraically.. however, I feel braindead right now, it isn't clicking. I tried factoring, nothing goes into either.. does it?

Answer 3

What about 1?

Answer 4

As in if you are using the method of what goes into the constant that multiplys to get the constant in front of the x^4 term and also adds to get the middle term. So more or less -1 and -1...

Answer 5

I'm beyond confused.. that doesn't sound familiar at all.. english please? haha

Answer 6

Ok I'll just do whatever else does on here and maybe you'll see it from the answer.

Answer 7

*left

Answer 8

\[(x^2-1)(x^2-1)=0\]

Answer 9

that's like precalc inception, I honestly would never think of that..

Answer 10

There are different ways to factor, I've always begun with the method I tried to describe. If you look, the two negative ones multiply to get the constant of 1 in front of the x^4 and add to get the -2 in the middle.

Answer 11

wait.. so it'd be like (x^2 - 1) (x^2 - 1) as you said, then.. how would you add the -2
if that's already a coefficient?

Answer 12

that's where it doesn't make sense, because I always remembered when factoring you can't take out any coefficients unless your simplifying?