If `s in A=3/5, cos B=-(12)/(13),\ w h e r e` A and B both lie in second quadrant, find the value of `sin(A+B)dot`

Explanation

Given `sinA = 3/5 and cosB = -12/13`

A And B lie in the second quadrant.

So sine function is positive and cosine function is negative.

We know that `cos A = -sqrt(1−sin^2A) and sin B = sqrt(1−cos^2B)`

Thus,` cosA=-sqrt(1-(3/5)^2)`

and `sinB=sqrt(1-(-12/13)^2)`


or `cos A =-4/5 `and `sin B=5/13`

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