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

r = 2 + 3 sin θ

Choices:
No symmetry
y-axis only
x-axis only
Origin only

Respuesta :

caylus
Hello,

Answer B: y-axis only
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Ver imagen caylus

Answer:

y-axis only.

Step-by-step explanation:

The given equation is

[tex]r=2+3sin \theta[/tex]

Notice that this equation is in polar form.

If [tex](r, \theta)[/tex] can be replace with [tex](r, \pi - \theta)[/tex] or [tex](-r, -\theta)[/tex], then the graph is symmetric to the line [tex]\theta = \frac{\pi}{2}[/tex], which is a vertical line.

Let's evaluate the given equation.

[tex]r=2+3sin \theta=2+3sin(\pi -\theta)= 2-3sin(- \theta)[/tex]

But, [tex]sin(-\theta)=-sin \theta[/tex]

So,  [tex]r= 2-3sin(- \theta)=2-(-3sin\theta)=2+3sin\theta=r[/tex]

Notice that the change produces the same equation.

Therefore, the given polar expression is symmetric to [tex]\theta = \frac{\pi}{2}[/tex], which is the y-axis only in the coordinate system.

So, the right answer is y-axis only.

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