Answer: a, c, e
Explanation:
a) True. If x=0, f(0)=c.
b) False. Considering the quadratic formula, we know the solutions are not always x=c.
c) True. This is a standard fact.
d) False. If the discriminant is not positive, there are less than two x-intercepts.
e) True. If you plug into the formula
, if b=0, then obviously the x-coordinate of the vertex is also 0.