URGENT !!! Please answer this using matlab, and focus on whats writtin in the red box!!!!

Part A A sine wave function g(t) is linearly increasing in frequency from 0 Hz at t=0s to 4 Hz at t#8s. The instantaneous frequency of the function at time t is f(t) = t. BH 105 The phase of a sine wave is 2n times the integrated frequency. Therefore g(t) = tu (2+ / sar) -(-3) 2 Plot the graph of this function. Add to the same figure (in a different colour) a graph of the same function sampled at 4 Hz using the stem command