Posted by Mary on Sunday, October 10, 2010 at 7:09pm.
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 x-axis.
Therefore, there are no real solutions.
But we have 2 imaginary solutions(roots) which can be cal. using the
quadratic formula.