16. b^2 - 4 a c = 144 ... a perfect square
... the roots (intercepts) are unequal integers
17. the equation of the axis of symmetry is the average of the intercepts
... a.o.s. ... x = (8 - 4) / 2
15. find the x-intercept by factoring.
y=x^2-4x-32
here is what i have
(x+4)*(x-8) =0
x=-4
x=8.
16. show how the value of the discriminant supports your conclusion from question 15.
17. How does the axis of symmetry relate to the x-intercept.
Thank you for the help.
2 answers
15 correct
16
the discriminant is b^2 - 4ac
for yours we get 16-4(1)(-32) = 144
which is a positive number and a perfect square,
so we have to different rational x-intercepts.
Remember if the discriminant is > zero , you have two real roots
if the discriminant is = zero, you have one root
if the discriminant is < zero, you have no real roots, the parabola would not cross the x-axis
17.
If you change the parabola to the vertex form , you get
y = (x - 2)^2 - 36 , (I assume you know how to do that)
the axis of symmetry is x-2 = 0
or
x = 2
which is the midpoint value between 8 and -4
16
the discriminant is b^2 - 4ac
for yours we get 16-4(1)(-32) = 144
which is a positive number and a perfect square,
so we have to different rational x-intercepts.
Remember if the discriminant is > zero , you have two real roots
if the discriminant is = zero, you have one root
if the discriminant is < zero, you have no real roots, the parabola would not cross the x-axis
17.
If you change the parabola to the vertex form , you get
y = (x - 2)^2 - 36 , (I assume you know how to do that)
the axis of symmetry is x-2 = 0
or
x = 2
which is the midpoint value between 8 and -4
7 answers