How do you find the critical points to graph f(x)=4sin(xπ2)?

1 Answer
Dec 12, 2015

(π2,0), (π,4), (3π2,0), (2π,4), (5π2,0)

Explanation:

By the five-point method, you need five points to graph the function, f(x)=4sin(xπ2). To find the five points, first find the five points for its parent function e(x)=sinx. Ignore the negative x values and its corresponding y values in the table below.

![bscstudent.buffalostate.edu)

Now that you have the five points for the parent function, use the mapping rule to apply transformations in order to find the five points for the transformed function, f(x)=4sin(xπ2).

Mapping rule: (x+π2,4y)

f(x)=4sin(xπ2)
Point 1.(0+π2,×x(4)0)××××x(π2,0)
Point 2.(π2+π2,×(4)1)××××x(π,4)
Point 3.(π+π2,×x(4)0)a××××(3π2,0)
Point 4.(3π2+π2,ix(4)(1))×××(2π,4)
Point 5.(2π+π2,×(4)0)××××x(5π2,0)

The transformed graph would look like:

![https://www.desmos.com/screenshot/6bf4rdat0g](useruploads.socratic.org)

Zoom in to check the five main points shown on the graph.