Sine wave with variable frequency

How to create a sine wave with its frequency continuosly varying without change in amplitude in Simulink . When we tried to create it the amplitude is also varying . Kindly help us

Answer 1

[Sam Chak]

Like this?

x = linspace(0, 6*pi, 6001);
y = cos(0)*sin(0.3*x.^2);
plot(x, y, 'linewidth', 1.5)

Use the Interpreted MATLAB Fcn block.