Algebra 2
posted by Mary on .
how to i graph the inequality :
y<x squared  3x + 15
whats my x and whats my y ? should i factor ?

To graph the inequality, graph :
Y= x^2  3x + 15 = 0,
Step 1. Find the coordinates (h,k) of
the vertex:
h = Xv = b/2a = 3/2 = 1.5,
Substitute 1.5 for x in the guad. Eq:
k = Yv = (1.5^2)  3*1.5 + 15 = 12.75,
V(1.5 , 12.75),
Step 2. Select values of x above and
below h(Xv) and cal. the corresponding value of y:
(1 , 19), (0 , 15), (1 , 13), (1.5 , 12.75), (2 , 13), (3 , 15).
The parabola does not cross the xaxis.
Therefore, there are no real solutions.
But we have 2 imaginary solutions(roots) which can be cal. using the
quadratic formula.