Aparabola has a focus of f(8.5,−4) and a directrix of x=9.5. what is the equation of the parabola? 1. 1/2y2+4y−1=x 2 .1/2y2−4y+1=x 3. −1/2y2+4y−1=x 4. −1/2y2−4y+1=x

Step-by-step explanation:

A parabola has a focus of F(8.5,−4) and a directrix of x=9.5.

General form of  horizontal parabola is

the distance between directrix and focus is the value of p

so p = 8.5 - 9.5 = -0.5

Focus is (h+p , k), given focus is (8.5, -4)

So k = -4 and h+p = 8.5

we know p = -0.5

h +p = 8.5

h - 0.5 = 8.5

so h= 9                   and k = -4

vertex is (h,k) that is (9, -4)

Now plug in the value in the general equation

, k= -4, h= 9 , p = -0.5

subtract 18 on both sides

Divide whole equation by -2

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong