Question

Is sin ab=1/2,then find value of 3sin-4sin^3

Answer 1

Sin(A + B) is the two parts of the opposite - all divided by the hypotenuse (9). Putting that into its trig form:sin(A + B) = sin A cos B + cos A sin B. Similarly , for sin(a-b) just replace '+ ' with '-' ,that's it.