I have gone through the first project. You will find my comments and your grade within the attached file here. Please download the graded file and look through it.
The first two problems are done fine. It is the third problem that caused some confusion. The best way was to create a function and let the function read the sine, cosine and fixed function and then it does the calculation for all three different conditions.
I am attaching the solution file here. What you both need to do is copy the function sdofresponse in a file and save it within maxima directory. Then open the maxima console and load the function with the load command as shown. Make sure that you have the right directory path. I gave my path but it may differ for you on where you save the function file. In maxima console execute the function by typing the function name as shown in the example. Then type the function when it ask for it at the command prompt as shown in the example. It should do all the calculation afterwards. You need to do it three times for sin, cos and constant loading.
Let me know if there is any problem in running this program.
Also, please resubmit your project 1 for regrading after incorporating all the suggestions I have.