So uhh what is your question?
Answer:
a)
,
, b)
,
, c)
,
.
Step-by-step explanation:
The equation of the circle is:

After some algebraic and trigonometric handling:


Where:


Finally,


a)
,
.
b)
,
.
c)
, 
Where:


The solution is 
The parametric equations are:


You said that P = I · R · T
Divide each side by I · R : P / (I·R) = T
D is correct. U is incenter of the triangle.
Answer:
3.333 hours
Step-by-step explanation:
Given the total distance is 30 miles, and boat 1 travels at 3 mph and boat 2 travels at 6 mph, and the time for both is the same. Distance is speed S times time T so
30 = D(boat 1) + D(boat 2)
30 = (S1 * T) + (S2 * T)
30 = 3T + 6T
30 = 9T
3.333 = T