# Finding maximum r-values of ploar equations

• May 30th 2009, 10:15 AM
jumpman23
Finding maximum r-values of ploar equations
How do you find the maximum of r and any zeros? My math teacher did not explain this well at all..

r= 8(√3-2sinΘ)
• May 30th 2009, 01:31 PM
pberardi
Quote:

Originally Posted by jumpman23
How do you find the maximum of r and any zeros? My math teacher did not explain this well at all..

r= 8(√3-2sinΘ)

I am sure that you would agree that r = 0 when (rad3 - 2sin(theta))= 0 yes?
So:
So now you need the sin inverse of rad three over two. Keep in mind that there are two correct answers or you can use pi2k.
• May 30th 2009, 02:53 PM
mr fantastic
Quote:

Originally Posted by jumpman23
How do you find the maximum of r and any zeros? My math teacher did not explain this well at all..

r= 8(√3-2sinΘ)

r = 0: Solve $0 = \sqrt{3} - 2 \sin \theta$.

Maximum value of r: Get it by inspection - Draw a graph of $r = \sqrt{3} - 2 \sin \theta$. Note that $r$ is the vertical axis and $\theta$ is the horizontal axis. Note: This is not the same as the the graph of the polar curve (which is drawn on a set of xy-coordinate axes).
• May 31st 2009, 07:49 PM
pickslides
for $y = Asin(x)+B$

$y_{min} = B+A$

$y_{max} = B-A$

expand your equation and it will be in this form.