Help on trig equations

[ShynastieMO18]

Can anyone help me with these trig identities?
1. Find sin(A+B) if SinA= 2/5 and SinB=1/4 where A and B are in quadrant I.
2.Find cos(A-B) if SinA=2/7 and SinB=1/3 where A and B are in quadrant I.
3. Find tan(A+B) if sinA=-2/3 and SinB=4/5 where A is in quadrant III and B is in quadrant II.

 

[Deleted member 4993]

Can anyone help me with these trig identities?
1. Find sin(A+B) if SinA= 2/5 and SinB=1/4 where A and B are in quadrant I.
2.Find cos(A-B) if SinA=2/7 and SinB=1/3 where A and B are in quadrant I.
3. Find tan(A+B) if sinA=-2/3 and SinB=4/5 where A is in quadrant III and B is in quadrant II.

Sin(A+B) = Sin(A)*Cos(B) + Cos(A)*Sin(B)

now cotinue....

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