3cot(x)-4tan(x)=0,
multiplying through by tan(x):
3-4tan2(x)=0=(√3+2tan(x))(√3-2tan(x)).
So tan(x)=√3/2 or -√3/2. So x=40.89° (0.7137 radians) approx.
General solution is 40.89+180n degrees (0.7137+nπ radians) where n is an integer.
Also, x=180-40.89+180n degrees=139.11+180n degrees (2.4279+nπ radians).