Trig  check my answers plz!
posted by Piper on .
1. (P 15/17, 8/17) is found on the unit circle. Find sinΘ and cosΘ
Work:
P= (15/17, 8/17)
cosΘ = a value
P = (a,b)
sinΘ = b value
Answer:
cosΘ = 15/17
sinΘ = 8/17
2. Should the triangle be solved beginning with Law of Sines or Law of Cosines. THen solve the triangle and found to the nearest tenth. a = 16, b = 13, c = 10.
Work:
c^2 = a^2 + b^2 2abcosC
10016^2+13^22*16*13cosC
100= 256+169 416cosC
100=425416cosC
325=416cosC
.78125=cosC
Answer: 38.6°, Law of Cosines is used
3. Should the triangle be solved beginning with Law of Sines or Law of Cosines. Then solve the triangle and round to the nearest tenth. A = 56 degrees, B = 38 degrees, a = 13.
Work:
SinA/a = SinB/b
sin56/13= sin38/b
Answer: 9.7
3. Find the exact value of tan(3pi)
Work: tan(3pi) = tan(3pi+2pi) = tan (pi) = tan (pi+2pi) = tan (pi) = sin(pi)/cos(pi) = (0)/(1) = 0
Answer : 0

correct.

simplify the expression tan 20 degrees +tan 25 degrees/ 1tan 20 degrees tan 25 degrees