how to make frequency shifting on simulink

if i have two sin waves block on simulink the first with variable frequency assume 10:30 hz and the second with fixed frequency f1 how to make the first with 10+f1:30+f1 i used frequency offset but it shift signal with f1 not center signal example sin(3t)*sin(4t)=a*cos(7t)+a*cos(t) i want only cos(7t) without filtering thanks

Answer 1

[Veera]

clc

clear all

close all

syms t w a

% Define the input signals

x1 = exp(-t) * heaviside(t);

x2 = dirac(t);

% Compute and display Fourier transforms

X1 = fourier(x1, w);

X2 = fourier(x2, w);

disp("Fourier transform of signal 1:")

pretty(X1)

disp("Fourier transform of signal 2:")

pretty(X2)

% Sum of Fourier transforms

X_sum = X1 + X2;

disp("Sum of Fourier transforms of signal 1 and signal 2:")

pretty(X_sum)

% Define frequency-shifted signals

x_left_shift = exp(-t) * heaviside(t) * exp(-a*t);

x_right_shift = exp(-t) * heaviside(t) * exp(a*t);

% Compute and display Fourier transforms of frequency-shifted signals

X_left_shift = fourier(x_left_shift, w);

X_right_shift = fourier(x_right_shift, w);

disp("Fourier Transform of frequency shift left signal is:")

pretty(X_left_shift)

disp("Fourier Transform of frequency shift right signal is:")

pretty(X_right_shift)

Answer 2

[Veera]

clc

clear all

close all

syms t w a

% Define the input signals

x1 = exp(-t) * heaviside(t);

x2 = dirac(t);

% Compute and display Fourier transforms

X1 = fourier(x1, w);

X2 = fourier(x2, w);

disp("Fourier transform of signal 1:")

pretty(X1)

disp("Fourier transform of signal 2:")

pretty(X2)

% Sum of Fourier transforms

X_sum = X1 + X2;

disp("Sum of Fourier transforms of signal 1 and signal 2:")

pretty(X_sum)

% Define frequency-shifted signals

x_left_shift = exp(-t) * heaviside(t) * exp(-a*t);

x_right_shift = exp(-t) * heaviside(t) * exp(a*t);

% Compute and display Fourier transforms of frequency-shifted signals

X_left_shift = fourier(x_left_shift, w);

X_right_shift = fourier(x_right_shift, w);

disp("Fourier Transform of frequency shift left signal is:")

pretty(X_left_shift)

disp("Fourier Transform of frequency shift right signal is:")

pretty(X_right_shift)