If sin alpha 35 and and sec beta 54 for a thirdquadrant an
If sin alpha = -3/5 and and sec beta = 5/4 for a third-quadrant angle a and a first-quadrant angle beta, find the following. sin(alpha + beta) tan(alpha + beta) the quadrant containing alpha + beta Quadrant I Quadrant II Quadrant III Quadrant IV
Solution
given sin =-3/5 , in Quadrant 3
cos =-((52-32))/5
cos =-4/5
given sec =5/4, in Quadrant 1
cos=1/sec =4/5
sin=((52-42))/5
sin=3/5
a)sin(+)=sincos +cossin
sin(+)=(-3/5)(4/5) +(-4/5)(3/5)
sin(+)=-24/25
cos(+)=coscos -sinsin
cos(+)=(-4/5)(4/5) - (-3/5)(3/5)
cos(+)=-7/25
b)tan(+)=sin(+)/cos(+)
tan(+)=(-24/25)/(-7/25)
tan(+)=24/7
c)(+) in Quadrant 3
