please feel free to check the precedent question for more info ( the exercise is divided to several questions that are related with each other.) :

Exercise 3: Find the suggested values by plotting the graphs until you can figure out the answer.

Repeating the above example, find one period of the function

f(x) = 120 sin(120 px).

(This is a bit tricky! Keep plotting until you clearly get one period shown in the viewing window.)

	Enter a number

When does f(x)=25-x -sin(x) cross the x-axis? (Guess an answer to within 1 decimal point.)

	Enter a number

4 Plotting functions with vertical asymptotes

Plotting functions with vertical asymptotes can cause troubles. For instance, suppose we want to plot the function f(x) = 1/sin(x) over the interval [0,p]. A first attempt may look like this:

>> x = linspace(0,pi); >> plot(x, 1./sin(x)) 

If you make this graph, you'll find that it doesn't look like what you would expect. In this case the function has a vertical asymptote at both endpoints 0 and p. This means that when the x values are close to the endpoints, the corresponding y values get to be very large. This is why the y-axis is labeled using scientific notation indicating 15 zeroes after the numbers. This makes this graph worthless for answering questions about f(x). The remedy is to replot, only this time avoiding the asymptotes:

>> delta = 0.1 >> x = linspace(delta, pi-delta) >> plot(x, 1./sin(x)) 

This is much better, allowing us to see the shape of the graph. We used a variable delta so that if we wanted to, it is easy to make changes.