Given a parabola with zeros at x=0 and x=4,
which of the following MUST be true:
I. The parabola opens upward
II. The parabola has a line of symmetry
at x=2
III. The parabola intercepts the y-axis at y=0

a. I only
b. III only
c. I and III only
d. II and III only
e. I, II, and III

Question

Given a parabola with zeros at x=0 and x=4, 
which of the following MUST be true:
I. The parabola opens upward
II. The parabola has a line of symmetry 
at x=2
III. The parabola intercepts the y-axis at y=0
 
a. I only
b. III only
c. I and III only
d. II and III only
e. I, II, and III

whpalmer4 · Answer

Does this parabola open upward or downward?  $y = x^2$  How about $y = -x^2$?

karinamtz0213 · Answer

it opens upward

whpalmer4 · Answer

yes, $y = x^2$ opens upward.  but what about $y = -x^2$?

karinamtz0213 · Answer

that i do not know

whpalmer4 · Answer

Note that this is $y = -1*x^2$ not to be confused with $y = (-x)^2$

whpalmer4 · Answer

Well get out a piece of paper and plot three points: x = -1, x = 0, x = 1 (using $y = -x^2$ to find the corresponding $y$ values

karinamtz0213 · Answer

then?

whpalmer4 · Answer

then you should be able to tell me if the parabola $y = -x^2$ opens upward or downward.

whpalmer4 · Answer

Well?