Here is the answer as shown in the picture:
Arc length = angle (in rad!!) * radius:
45 degree = pi / 4 rad
Arc length = pi/ 4 * 15 = 15/4*pi feet or approx. 11.781 feet
Also in this case only, 45 degrees is 1/8 of the whole circle, so Arc length = 2pir/8 = pi/4*r, but only this case. the first formula always works!
We simply take the amount he needs no earn ($500) subtract what he gets for each sale ($50) and divide with the percentage he gets (2% = 0.02)
500-50 = 450
450/0.02 = 22500
The salesperson has to sell a car for $22500 in order to earn $500 himself
A graph shows the function can be factored as
f(x) = (x -1)((x-8)² +1)
There is one real root and there are two complex roots. The latter can be found from the vertex form factor:
(x - 8)² + 1 = 0
(x - 8)² = -1
x - 8 = ±√(-1) = ±i
x = 8 ± i
The zeros of the function are {1, 8-i, 8+i}.