Answer:
The equation of the parabola is 
.
Step-by-step explanation:
Since the directrix is of the form 
, the parabola is vertical. The vertex of the parabola (
) is the midpoint between the focus (
) and a point of the directrix (
), that is to say:
(1)
If we know that 
and 
, then the coordinates of the vertex of the parabola:
The vertex factor (
) is the distance of the focus with respect to the vertex:
![p = \sqrt{[F(x,y)-V(x,y)]\,\bullet \,[F(x,y)-V(x,y)]}](https://tex.z-dn.net/?f=p%20%3D%20%5Csqrt%7B%5BF%28x%2Cy%29-V%28x%2Cy%29%5D%5C%2C%5Cbullet%20%5C%2C%5BF%28x%2Cy%29-V%28x%2Cy%29%5D%7D)
(2)
If we know that and , then the vertex factor is:
The equation of the parabola in the vertex form is described below:
(3)
Where:
- Independent variable.
- Dependent variable.
- Coordinates of the vertex.
If we know that 
and , then the equation of the parabola is .
Answer: $169
Step-by-step explanation: The expression 25 + 18 x 8 represents the amount she will pay if she participates for 8 months.
Multiply 18 x 8 to find the cost for 8 months. $18 x 8 = $144.
Now add $25 to $144, which equals $169
Answer:
After 1 second, the ball will reach a maximum height of 16 feet
Step-by-step explanation:
The height of the ball after t seconds: h(t) = -16t^2 + 32t
The graph of this quadratic function is parabola which opens downwards. The vertex of a quadratic equation is the maximum or minimum point on the equation's parabola
t = -b/2a = -(32)/2(-16) = -32/-32 = 1 second
then
h(t) = -16(1)^2 + 32(1) = -16 + 32 = 16
After 1 second, the ball will reach a maximum height of 16 feet
I think the answer is 6.6
