
Mike D. answered 09/26/20
Effective, patient, empathic, math and science tutor
Well as both sin (2x) and 5x > 0, you need to use L'Hopitals rule (keep differentiating the numerator and denominator and evaluate at x=0 until denominator is non zero)
So lim x>0 sin (2x) / 5x = lim x > 0 2 cos (2x) / 5
Denominator is non zero so we can evaluate the limit which is 2 cos (0) / 5 = 2/5
Mike