Use the given information to find the exact value of the expression.

sin α =21/29 , α lies in quadrant II, and cos β =15/17 , β lies in quadrant I Find sin (α - β).

Question

Use the given information to find the exact value of the expression. 

sin α =21/29 , α lies in quadrant II, and cos β =15/17  , β lies in quadrant I Find sin (α - β).

anonymous · Answer

Remember how to expand $\sin(α - β)$?

anonymous · Answer

@Calcmathlete ,   like this?

sin(a-b) = s  i  n  (   a    -   b   )

cwrw238 · Answer

lol

anonymous · Answer

lol. I thought you were going to hijack the question XD
@sarah43 Remember the following?
$$\sin(α - β) = \sinα\cosß - \cosα\sinß$$

anonymous · Answer

yes i did it but im not getting one of the answer choices

anonymous · Answer

What did you get and how did you get it?

anonymous · Answer

sin(21/29−15/17)=(sin21/29)(cos15/17)−(cos21/29)(sin15/17)

@Calcmathlete

campbell_st · Answer

draw some triangles

|dw:1343510549326:dw|

find x and y using pythagoras... and then you can solve the problem

y will be negative