ANSWER

EXPLANATION
Since the directrix is

the axis of symmetry of the parabola is parallel to the y-axis.
Again, the focus being,

also means that the parabola will open upwards.
The equation of parabola with such properties is given by,

where

is the vertex of the parabola.
The directrix and the axis of symmetry of the parabola will intersect at

The vertex is the midpoint of the focus and the point of intersection of the axis of the parabola and the directrix.
This implies that,

and

The equation of the parabola now becomes,


Thus, the distance between the vertex and the directrix.
This means that,

Since the parabola opens up, we choose

Our equation now becomes,

This simplifies to

or

This is the same as,

The correct answer is D .
slope intercept form
y=mx+b
where m is the slope and b is the y intercept
if we change from point slope form
y-y1 = m(x-x1)
we distribute
y-y1 = mx -x*x1
then add y1 to each side
y = mx -x*x1+y1
remember x and y are variables and should stay in the equation
m,x1,y1 are numbers from the problem
you may have to calculate the slope (m) from the formula
m = (y2-y1)/(x2-x1) from two points on the line
Answer:
40
Step-by-step explanation:
tell me if im right
Answer:
Ok
Step-by-step explanation: