Question

I am working on this trig problem which involves law of cosines. Have it partially done but need some help.
Picture attached.

Answer 1

so I found sin(A) to be 15/100 = .15
and A to be .15
Then I used sin^2(A)+cos^2(A)=1 to solve for cos(A) = .99.
I used pythagorean theorem to find third side of right triangle to be 98.87.
I need to find the rest and don't know how.

Answer 2

I know that a = sqrt(b^2+10000-200b cos(A))
but I don't know how to find b.

Answer 3

Suppose an officer is in a car 15 feet off the side of a road (point B in Figure 1). A vehicle approaches traveling 70 mph (point A in figure 1). We want to calculate the speed of the car reported by the radar unit when the car is 100 feet away.
 We need to compute the speed of the car by measuring the difference in the length of BA and the length of BC. Generally, the length of AC (the true distance traveled by the car in t seconds) is not the same as the difference in lengths of and (the distance the radar gun uses to compute the speed of the car). Where would the police officer need to be positioned in order for the distance the car travels and the distance the radar gun measures exactly the same?
 We need to compute the length of BC as the first step in obtaining a function for computing the speed reported by the radar gun. To do this, we will use the formula (law of cosines) where a is the length of BC, b is the length of AC, and c is the length of BA.
 Explain why the above equation is valid.
 Find
 Determine an expression for b in terms of rate and time with the rate in feet per second and time as a variable in seconds. Remember, the car is traveling at 70 mph.
 Substitute your expressions for b and cos(A) into the above equation. You should now have a function where your input, t is in seconds and your output, a is in feet.

Answer 4

Hero, it says you replied, but I can't see it...

Answer 5

I will post a solution soon. It's ridiculous to say the least

Answer 6

Cool. Thanks man!

Answer 7

I finished it hours ago but something amazing happens when I try to solve for b.

Answer 8

thanks!