SOLUTION: tan α = 12/5, α lies in quadrant III, and cos β = -20/29 , β lies in quadrant II Find sin (α + β). A) -152/377 B)352/377 C) 345/377 D)135/377

Algebra ->  Trigonometry-basics -> SOLUTION: tan α = 12/5, α lies in quadrant III, and cos β = -20/29 , β lies in quadrant II Find sin (α + β). A) -152/377 B)352/377 C) 345/377 D)135/377      Log On


   

Question 769551: tan α = 12/5, α lies in quadrant III, and cos β = -20/29 , β lies in quadrant II Find sin (α + β).
A) -152/377
B)352/377
C) 345/377
D)135/377
Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
tan%28alpha%29=12%2F5%29
so in III
r=sqrt%2812%5E2%2B5%5E2%29=13
sin%28alpha%29=-12%2F13
cos%28alpha%29=-5%2F13
in II
sin%28beta%29=sqrt%281-%28-20%2F29%29%5E2%29=21%2F29

sin%28alpha%2Bbeta%29=sin%28alpha%29cos%28beta%29%2Bcos%28alpha%29sin%28beta%29