Well, here's an exponential decay and an exponential decay shifted up by 7 units:
.
Undefined.
limit as x → 0 of 0^x is 0
limit as x → 0 of x^0 is 1
(20/100)*Full = 800
Full = 800*100/20 so Full = 4000 litres
A regular 7-sided polygon can be thought of as being made of 7 isosceles triangles. Each triangle has an apex angle theta = 2pi/7. The height is h = 2.5 and half the base length is b = h*tan(theta/2). Hence the overall area of the polygon is:
A = 7*b*h or A = 7*2.5*tan(pi/7)*2.5 or A ≈ 21.07
Volume of cone = (1/3)*pi*r^2*h. r = radius, h = height.
As below:
Here are answers to the first three. Let's see if you can make use of these to do part (iv) yourself:
Use Pythagoras theorem. The distance between the cars, 10km, is the hypotenuse of a right angled triangle, one leg of which is 6km and the other of which is, say, x km
x = sqrt(10^2 - 6^2) km.
You can crunch the numbers.
8 = 2^3 so 1/8 = 1/2^3 → 2^(-3)
x = -3
+33667 
