Step 1.8 Now lets return the cosine phase angle back to 0 radians, and plot both the sine and cosine waves onto a single graph for comparison. The red plot is the cosine wave while the blue plot is the sine wave. The cosine plot leads the sine plot by 90 degrees or /2 radians. (Note: Make sure to close the plot window before running the script!)

clc clear A1=3 A2=5 f1=150 f2=150 sphase=0 bphase=0 t=0:0.0001:0.01 s=A1*sin((2*pi*f1*t)+sphase) b=A2*cos((2*pi*f2*t)+bphase) yyaxis left %this command places the y scale on the left sideplot(t,s)

ylim([-8 8]) ylabel('s=A1*sin((2*pi*f1*t)+sphase)') yyaxis right %this command places the y scale on the right sideplot(t, b) ylim([-8 8]) ylabel('b=A2*cos((2*pi*f2*t)+bphase)') xlabel('Time (seconds)') title('Sine and Cosine Waveforms')

Step 1.9 Using the MatLab code in step 1.8, modify the sine sphase, by +90 degrees or +pi/2 radians, and keep the cosine wave, bphase, at 0 degrees phase angle.

Question 1.9 Select the best answer regarding your observation from step 1.9.

a. both s(t) and b(t) appear as identical sine waves b. both s(t) and b(t) appear as identical cosine waves c. both s(t) and b(t) appear as cosine waves; however, their amplitudes differ d. s(t) appears as a cosine wave while b(t) appears as a sine wave

Plot 1.9 - Sine Cosine Wave Plot Submission: Submit (i.e., copy/paste) the MATLAB plots from step 1.9above into the IT300 Virtual Lab Plot Submission document template.

Step 1.10 Now try plotting the following carrier waves with s(t) appearing on the left and b(t) appearing on the right. Place both plots onto a single graph as you did in steps 1.8 and 1.9.

s(t) = 5sin(2250t - ) b(t) = 5cos(500t + 0)

Question 1.10 What are the differences between the two plots a(t) and b(t) from step 1.10?

a. s(t) and b(t) have different frequencies b. s(t) and b(t) differ in phase angle c. s(t) and b(t) differ in amplitude d. both a and b

Step 1.11 Set the phase angles for s(t) to pi/2 radians, and b(t) to 0. Set the frequency for s(t) and b(t) equal to 300 Hz.

Question 1.11 Select the correct observation for s(t) and b(t)

a. plots are same in amplitude b. plots are same in frequency c. both plots appear as cosine waves. This is because the sine waves lag cosine waves by 90 degrees.

By advancing the sine wave s(t) by 90 degrees, it appears identical to b(t). d. all are correct