Matrixes must agree error

I have the .* to do element by element math, however, it keeps coming back with matricies must agree errors

%% Section 1: Initalization of Variables 
f = [0, 5, 10, 20]; %frequencies
t = 0:0.1:pi; %numbers for time
v =-5+exp(-5.*t).*((4.*cos(f.*t))+9.*sin(f.*t)); %equation %% Error here



%% Section 2: Processing

%applying the array f to each voltage
v1 = [v, f(1)];
v2 = [v, f(2)];
v3 = [v, f(3)];
v4 = [v, f(4)];


 
%% Section 3: Result Output

plot(v1, v2, v3, v4)
title('Voltage in a RLC circuit')
xlabel('Frequncy')
ylabel('Volts')

Answer 1

[Bandar]

If you would like to carry out element-by-element mutliplication, vectors must have same size. In your case f has 4 elements whereas t has 32 elements.