## Dido525 2 years ago Find the domain of f(x)

1. Dido525

I know the square root argument must be grater to 0 but I can solve the inside for x> 0 .

2. Dido525

@Callisto @UnkleRhaukus

3. Dido525

@jim_thompson5910

4. Dido525

$\sqrt{-x^4+3x^2+4}+1$

5. Dido525

That's the right one sorry :P .

6. Aylin

$\sqrt{-x^{4}+3x^{2}+4}$ $-x^{4}+3x^{2}+4 \ge 0$I'm going to try to divide the equation by (x^2+1)$\frac{ -x^{4}+3x^{2}+4 }{ x^{2}+1 }=-(x^{2}-4)=-(x+2)(x-2)$(The above was done on paper since it would be too tedious to put in the calculation here). But this shows that $-x^{4}+3x^{2}+4=-(x+2)(x-2)(x^{2}+1) \ge 0$You should be able to get the rest. (x^2+1 was attempted since all of the powers of x were divisible by 2, and all of the coefficients had 1 as their only common factor).

7. Dido525

Thanks a lot :) .