Which of the following equations is used to solve for side a?

Determine the measure of side a ( to the nearest degree and minute).

sin a = sin A cos B
sin A = cos a cos B
cos a = cos B/ sin A
cos a = cos A/ sin B

The equation that is used to solve for side a is:

cos a = cos A/ sin B

To solve for side a, the equation you can use is:

cos a = cos B / sin A