SOLUTION: Find sin2x from the given information. sinx=-(3/5) x in Quadrant III

Use this formula of Trigonometry

sin(2x) = 2*sin(x)*cos(x).

You just know that sin(x) =  (it is given).

Based on it, you can calculate

cos(x) = - = - = - = - = - = -.

Notice that the sign before the square root is negative, since the function cosine is negative for x in Q3.

Now you are on the finish line to calculate sin(2x):

sin(2x) = 2*sin(x)*cos(x) =  = .

Answer.  sin(2x) = .