Answer:Solutions are: x = -5, x = -4/5.
Step-by-step explanation:
The answer you picked is correct.
Remember that transformation between Cartesian and polar system are:
x=r*cos(α)
y=r*sin(α)
From this we can conclude that:
r=√(x^2 + y^2)
Using trigonometry transformations we can write:
r=sin(2α) = 2sin(α)cos(α)
Now we can multiply both sides with r^2:
r^3 = 2(r*sin(α))*(r*cos(α))
Now using some replacements we can write:
(x^2 + y^2)^(3/2) = 2*x*y
You're given the y-intercept, which is (0,5), so to complete the slope intercept form, you now need to find the slope. slope is the change in y over the change in x, so take points (4,-1) and (2,2) for instance and apply the formula; -1-2= -3 and 4-2=2, so the change in y is -3 and the change in x is 2. to find the slope, you divide change in y by change in x, which is -3/2. from here, you can gather that the slope intercept form is y= -3/2x + 5
Since x represents the year, year 15 will be 15 years.
Plug in "15" as your "x"
y = -2(15)^2 + 36(15) + 6
15^2 = 225 (Exponents come before multiplication)
y = -2(225) + 36(15) + 6
y = -450 + 540 + 6
y = 90 + 6
y = 96
<em>The answer is B</em>
