Here's the question you clicked on:
Dido525
Find the domain of f(x)
I know the square root argument must be grater to 0 but I can solve the inside for x> 0 .
@Callisto @UnkleRhaukus
\[\sqrt{-x^4+3x^2+4}+1\]
That's the right one sorry :P .
\[\sqrt{-x^{4}+3x^{2}+4}\] \[-x^{4}+3x^{2}+4 \ge 0\]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).