Question 260145
f(x)= x^4 - 10x^2 + 9


f(x)= (x-3) (x-1) (x+1) (x+3)
We know from the x^4 that there are four solutions.
Is almost a parabola but between -3 and 3 it goes up and down 
 y  goes down to -10 (twice) and up +10 once  between -3 and +3