Math
posted by Belden on .
1. Find the value of Sin^1(1/2)
a. 30 degrees
b. 30 degrees
c. 150 degrees
d. 330 degrees
2. Find the exact value of cos(420 degrees)
a. 1/2
b. 1/2
c. sqrt of 3/2
d. sqrt of 3/2
3. p(9/41, 40/41) is located on the unit circle. Find sin theta.
a. 40/41
b. 9/41
c. 9/40
d. 40/9
4. In triangle ABC, C = 60 degrees, a=12, and b=5. Find c.
5. Which triangle should be solved by beginning with the law of Cosines?
a. A=115 degrees, a=19, b=13
b. A=62 degrees, B=15 degrees, b=10
c. B=48 degrees, a=22, b=5
d. A=50 degrees, b=20, c=18

1. Both a and d are correct. 30 and 330 degrees are the same angle
2. d
3. b theta = sin^1 (9/41)/1, siunce it is on a unit circle.
Note that sqrt[(9/41)^2 + (40/41)^2] = 1
4. Use the law of cosines when you know two adjacent sides and the included angle (which would have a capital letter designation different from the sides). Only one of the choices fits this criterion.