Its increasing 40 miles for every hour
Okay, you will need to use the law of cosines for this problem.
The Law of Cosines states (in this case): a^2 = b^2 + c^2 - 2 * b * c * cos A, where "a" is the side opposite angle A (7 inches), and b and c are the other two sides.
Plug the numbers in and you get: 7^2 = 5^2 + 9^2 - 2 * 5 * 9 * cos A, or:
49 = 25 + 81 - 90 * cos A.
Subtract (25 + 81) from both sides to get:
-57 = -90 * cos A.
Divide by -90 on both sides:
cos A = 19/30
To find A, you do the inverse trigonometric function to get:
cos^-1 of (19/30) = A.
I don't have a calculator that can do this right now, but if you plug the left side of the above equation into it (make sure it is in degrees, not radians), you should get A.
Answer:
I got 55..and I also got 50.......
Answer: 12.5 or 12 1/2
Step-by-step explanation:
