Question 745825
If α and β are acute angles such that csc (α) = 17/15 and cot (β) = 3/4, find the following. 
a. sin(α+β) 
b.tan(α+β)
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use a & b for (α & β
csc(a)=17/15
sin(a)=15/17
{{{cos(a)=sqrt(1-sin^2(a))=sqrt(1-(225/289))=sqrt(64/289)=8/17}}}
{{{tan(a)=sin(a)/cos(a)=(15/17)/(8/17)=15/8}}}
...
cot(b)=3/4
tan(b)=4/3
opposite side=4
adjacent side=3
hypotenuse=5
sin(b)=4/5
cos(b)=3/5
..
sin(a+b)=sin(a)cos(b)+cos(a)sin(b)=(15/17)(3/5)+(8/17)(4/5)=(45/85)+(32/85)=77/85 
tan(a+b)=(tan(a)+tan(b))/(1-tan(a)*tan(b))
=[(15/8)+(4/3)]/[1-(15/8)(4/3)]
=[45/24+32/24]/[1-60/24]=77/24/-36/24=-77/36
..
Check with calculator:
sin(a)=17/15
a≈61.9275º
tan(b)=4/3
b≈53.1301
a+b=115.0526
sin(a+b)=sin(115.0526)≈0.9059
exact ans=77/85≈0.9059
tan(a+b)=tan(115.0526)=-2.139..
exact ans=-77/36≈-2.139..