Can anyone help me simulate this exercise on Ltspice? I've learned to use it but can't work with it very well yet.

I would like to calculate Va(t) with the simulation.

With this I got an empty simulation

Is this correct: 60cos(50t + 20°) = 60sin(50t - 70°)?

50t = 50 / 3.14 = 78.53Hz

60cos(50t + 20°) = 60sin(78.53Hz - 70°)?

Thanks in advance