How do you graph y=xcosx?

1 Answer
Mar 24, 2016

The graph is oscillatory between y = x and y=x. The expanding waves meet x-axis at origin and x=±(2n1)π2, n =1, 2, 3, 4, .

Explanation:

|y|=|xcosx||x|

If (x, y) is on the graph, so is (x,y). So, the graph is symmetrical about the origin.

y = 0, when x = 0 and cos x =0.
cos(±(2n1)π2)=0, for n = 1, 2, 3, ...
So, the curve meets x-axis at (0, 0), (+-(2n-1)pi/2, 0)#, n= 1, 2, 3, ...

Limits x± of x cos x are indeterminate.