
We know that : (a - b)(a + b) = a² - b²

We know that : 1 - sin²x = cos²x



We know that : sec²x = 1 + tan²x







The sketch of the parabola is attached below
We have the focus

The point

The directrix, c at

The steps to find the equation of the parabola are as follows
Step 1
Find the distance between the focus and the point P using Pythagoras. We have two coordinates;

and

.
We need the vertical and horizontal distances to find the hypotenuse (the diagram is shown in the second diagram).
The distance between the focus and point P is given by

Step 2
Find the distance between the point P to the directrix

. It is a vertical distance between y and c, expressed as

Step 3
The equation of parabola is then given as

=


⇒ substituting a, b and c


⇒Rearranging and making

the subject gives
The answer i believe is 4000
392 / 500 double and take one decimal place to see percentage
52/500
56/500 e.g. 56*2 = 112 now take 1 decimal so it is 11.2%
now divide each by 20
Converting -4 to polar form gives
.
Then the 4th roots of -4 would be the numbers

where <em>k</em> is taken from {0, 1, 2, 3}.
So we have



