Given:
The focus of the parabola is at (6,-4).
Directrix at y=-7.
To find:
The equation of the parabola.
Solution:
The general equation of a parabola is:
...(i)
Where, (h,k) is vertex, (h,k+p) is the focus and y=k-p is the directrix.
The focus of the parabola is at (6,-4).

On comparing both sides, we get

...(ii)
Directrix at y=-7. So,
...(iii)
Adding (ii) and (iii), we get



Putting
in (ii), we get



Putting
in (i), we get


Therefore, the equation of the parabola is
.
Answer:
CE= 9cm, DE= 5cm, CD= 10.2956cm
Step-by-step explanation:
Let E be the point of the other triangle.
Using Pythagoras' Theorem,
CD= square root symbol (CE^2 + DE^2)
= square root symbol (9^2+5^2)
= 10.2956cm (6 sf)
Answer:
C = pi * d = 2 * pi *r
Step-by-step explanation:
The circumference of a circle is the distance around the circle. It can be found by multiplying the diameter times pi.
C = pi * d
We can replace the diameter with twice the radius
C = pi * 2 * r = 2 * pi *r
Answer:
Step-by-step explanation:
