For three values of x and y confirm that ln xy ln x ln y

Question

To use in Matlab. I need code for my Matlab class.

1. For three values of x and y, confirm that ln (xy) = ln x + ln y.( using matlab with code)
2. For three values of x in the range 0<=x<=2*pi, confirm that tan(2x)=2tanx/(1-tan^2(x))
3. The equation e^(-0.2x) sin(x+4) = 0.4  has four solutions in the interval-5<x <5. Find these four solutions.