(a) Write a Matlab function signalx that evaluates the following signal at an arbitrary set of points:
x(t) = ∫ 2e^ t+2, −3 <_ t <_ −1
2e^−t cos 2πt, −1 <_ t <_ 4
0, else
That is, given an input vector of time points, the function should give an output vector with the values of x evaluated at those time points. For time points falling outside [−3, 4], the function should return the value zero.
(b) Use the function signalx to plot x(t) versus t, for −6 <_ t <_ 6. To do this, create a vector of sampling times spaced closely enough to get a smooth plot. Generate a corresponding vector using signalx. Then plot one against the other.
(c) Use the function signalx to plot x (t − 3) versus t.
(d) Use the function signalx to plot x (3 − t) versus t.
(e) Use the function signalx to plot x (2t) versus t.

Write a grading program for a class with the following grading policies: a. there are two quizzes, each graded on the basis of 10 points. b. there is one midterm exam and one final exam, each graded on the basis of 100 points. c. the final exam counts for 50% of the grade, the midterm counts for 25%, and the two quizzes together count for a total of 25%. (do not forget to normalize the quiz scores. they should be converted to a percentage before they are averaged in.) any grade of 90 or more is an a, any grade of 80 or more (but less than 90) is a b, any grade of 70 or more (but less than 80) is a c, any grade of 60 or more (but less than 70) is a d, and any grade below 60 is an f. the program will read in the student’s scores and output the student’s record, which consists of two quiz and two exam scores as well as the student’s average numeric score for the entire course and final letter grade. define and use a structure for the student reco