Question

Determine if the graph is symmetric about the x-axis, the y-axis, or the origin.

r = 4 cos 5θ

Answer 1

y-acis

Explanation:

the function graph is symmetric about

- y-axis when it is an even function

-the origin ehen it is an even function

A symmetrical graph about the x-axis is not a function graph

f(×) is a even if and only if f(×) =f(×)

f(×) is a odd if and only f(×)=f(×)

We have the function r(0) = 4cos (50)

(only symmetry about the y-acis or about the origin)

Check r(-0)

r(-0) = 4cos (5-0) = 4cos (-50 = 4 cos (50)

Used cos (-× = cos ×

We have r(0). Therefore the graph of r(0) is symmectric about the y-axis.