Ok what if the equation is:

L * di/dt + (R1+R2)i + q/C = U

L = 4
R1 = 8
R2 = 6
C = 4
u= 10cos8t

i(0) = 1
i´(0) = 1

I must calculate i(t) and plot the answer i.

Ok what if the equation is:

L * di/dt + (R1+R2)i + q/C = U

L = 4
R1 = 8
R2 = 6
C = 4
u= 10cos8t

i(0) = 1
i´(0) = 1

I must calculate i(t) and plot the answer i.

@Carl Love 

i(0) = 0
q(0) = 2

the answe should be:
q(t) = -3e^-3 + 4e^-2t + e^-t

Is it possible to solve and plot?

Thank you. I appreciate it.

How about this diff. equation.

a) How can i use laplacetransform to solve the equation reference to i₁, i₂, i₃ ?

i₁ = i₂ + i₃ 
2i₁ + i₂ + 2i₁ = 30 + 20cos5 + 114sin5  
1/50 i₃ + 4i₃ - 2 i₂ = 0  

i₁(0) = 0

i₂(0)=0

i₃(0)=0

b) Plott the equation.

Thank you. I appreciate it.

How about this diff. equation.

a) How can i use laplacetransform to solve the equation reference to i₁, i₂, i₃ ?

i₁ = i₂ + i₃ 
2i₁ + i₂ + 2i₁ = 30 + 20cos5 + 114sin5  
1/50 i₃ + 4i₃ - 2 i₂ = 0  

i₁(0) = 0

i₂(0)=0

i₃(0)=0

b) Plott the equation.