Answer :
Answer:
tan (θ+x)= -33/56
sin (θ+x)=33/65
Step-by-step explanation:
cosθ= -4/5 , sin x = -12/13
cosθ= -4/5; θ is in the third quadrant=> sinθ=-√(1-cos² θ)
sinθ=- √(1-16/25)=- √(9/25)=-3/5
sinx= -12/13; x is in the fourth quadrant=> cosx=+√(1-sin²x)
cosx=√(1-144/169)= √(25/169)=5/13
tgθ= sinθ/cosθ=(-3/5)/(-4/5)=3/4
tgx= sinx/cosx=(-12/13)/(5/13)= -12/5
tan (θ+x)=(tgθ+tgx)/(1-tgθ*tgx)
tan (θ+x)=(3/4-12/5)/(1+3/4*12/5)=(-33/20)/56/20)= -33/56
sin (θ+x)=sinθcosx+coxθsinx=-3/5 *5/13 +-4/5 * (-12/13)=-15/65+48/65=33/65