find the answer to each function

Question

If  in quadrant III, then

    

    

Answer 1

If x is in quadrant 3 and sinx = -3/5, then cosx is also negative and cosx = -√[1-sin²x] = -4/5

sin(2x) = 2sinxcosx

cos(2x) = cos²x - sin²x

tan(2x) = sin(2x) / cos(2x)

Plug in the values for sinx and cosx into the double angle formulas given above.