Homework Help: Trig

Posted by Sierra on Wednesday, November 7, 2012 at 11:27am.

Give: a=alpha B=beta
csc a= 2
pi/2<a<pi
secB=-3
pi/2<B<pi

1)find sin(a+B)
2)find tan(a-B)
3)cos B/2
4)sin a/2

Trig - Steve, Wednesday, November 7, 2012 at 11:32am
in QII,

if csc a = 2,
sin a = 1/2
cos a = -√3/2
tan a = -1/√3

if sec B = -3,
cos B = -1/3
sin B = √8/3
tan B = -√8

Now it's just plug and chug, using your sum-of-angles and half-angle formulas. Come on back if you get stuck.

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