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
P= (-15/17, -8/17)
cosΘ = a value
P = (a,b)
sinΘ = b value
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.
c^2 = a^2 + b^2 -2abcosC
100= 256+169 -416cosC
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.
SinA/a = SinB/b
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