Question 616888
In order to solve these problems, we will need to be able to figure out what cos(B) and sin(A) are.<br>
We're told that cos(A) = 0.42. Cos is positive in both the 1st and 4th quadrants. sin(A) will be positive if A terminates in the 1st quadrant but it will be negative if A terminates in the 4th.<br>
Similarly, we cannot figure out the sign of cos(B) without knowing where B terminates.<br>
So without information that could be used to determine the quadrants for A and B, these problems cannot be done. Either you or your teacher have left out something important.