(x+3)(x-1)
Can someone assist me with this? I'm supposed to find the range of valid answers
typically I'd just factor the left to figure out the zeros to get my critical points, then check each area to find the valid ranges. However, I can't factor the equation...unless I'm mistaken, it's not factorable. How do I get the answer?
In order for this to be < 0,
one factor must be positive and the other negative.
Hence, if x+3 is positive, x > -3.
x-1 remains negative until x=1.
Hence -3 < x < 1
Also if x+3 is negative, x < -3
There is no way this range of x allows x-1 to be positive however.
Therefore -3 < x < 1.
Or, the graph is a parabola with the minimum under the x axis.
Hence, it's negative between the roots.