Question

Graph the pilar equation: r=2cos(2theta)

Answer 1

We want to plot a graph of ;

$r=2\cos (2\theta)$

Using the formula;

$r=a\cos (n\theta)$$\begin{gathered} \text{Where a}\ne0 \\ \text{and } \\ n\text{ is an integer }>1 \end{gathered}$

The graph will have the rose form.

And if the value of n is odd, the rose will have n petals, if the value of n is even, the rose will have 2n petals;

For the given question;

n = 2 (even)

So, the rose will have;

$\begin{gathered} 2n=2(2) \\ =4\text{ petals} \end{gathered}$

The graph is shown below;