t=0:0.0001:0.1;x_FM= cos(fc*t+kf*quadgk(@(s)Fm(s),0,w));

As an AI language model, I cannot run this code, but I can explain it to you.

This code defines a time vector t from 0 to 0.1 with a step size of 0.0001. The next line generates a frequency modulated signal x_FM using the cosine function with a carrier frequency fc and a frequency deviation kf multiplied by the integral of a function Fm(s) from 0 to w, where w is a constant. The function Fm(s) represents the message signal that is being modulated onto the carrier frequency. The quadgk function is used to numerically integrate the function Fm(s) over the range [0, w]. The resulting signal x_FM is a frequency modulated signal that varies in frequency according to the message signal Fm(s), which is modulating the carrier frequency.