30. -3a^2= -3-6^2 is this correct? And I have to evaluate o I am not good at that so if u can help THANK YOU so much! a=-6

The answer is, the streetlight is 18 inches tall.

Idon't see any graph, however the graph of the function : f(x) = x²-2x+3 is a parabola: 1) open upward (since a> 0)2) it intersects y-axis in 3 (y=3)3) its axis of symmetry is x = +1 ( -b/2a)4) it's minimum is y = -2, so its vertex is (1,-2)5) it doesn't intersect the x-axis since discriminant < 0