How can I modify this code for frequency modulation to use freq deviation instead of a modulation index?

I found a way to plot Frequency Modulated signals in the time domain, however, it uses a modulation index instead of Frequency Deviation.

How can I alter this code to use Frequency Deviation instead?

% Carrier Freq (Hz)
fc = 1200;

% Modulating Signal Freq (Hz)
fm = 60;

% Modulation Index
m = 10;

% Carrier Amplitude
Ac = 10;

% Signal Amplitude
Am = 1;

% Frequency deviation
f_delta = 300;

% Number of samples
numSamples = 2^14;

t = linspace(0, 0.05, numSamples);

% Carrier signal
c = Ac * sin(2*pi*fc*t);

% Modulating signal
M = Am * sin(2*pi*fm*t);

y = cos(2*pi*fc*t + (m.*sin(2*pi*fm*t)));

plot(t,y);

xlabel('Time');
ylabel('Amplitude');
title({'FM Signal'});

Answer 1

[Vishwa]

Modulation Index is nothing but ratio of peak frequency deviation and highest frequency component.

Hence,

y = cos(2*pi*fc*t + ((f_delta/fm).*sin(2*pi*fm*t)));