Answer :
Answer:
[tex]y=-x^{2} -3x-3[/tex]
Step-by-step explanation:
a parabola is the graph of a quadratic equation, so the general equation is
[tex]y=ax^{2} +bx+c[/tex]
If the directrix is negative, it means the graph opens down, so a is -
and c is -3
this gives us
[tex]y=-x^{2} +bx-3[/tex]
all we need now is what is b
b is the y intercept for [tex]y=mx+b[/tex]
to find the y intercept, we plug in 0 for x
[tex]y=-x^{2} +bx-3\\y=-0^{2} +b(0)-3\\y=0+0-3\\y=-3[/tex]
so the y intercept is -3
so the equation is
[tex]y=-x^{2} -3x-3[/tex]