Hi

Show that the polar equation r= a cos x + b sin x where ab not equal 0 represents a circle and find its center and radius

I really have no idea where to start - any ideas at all??

Thanks

Struggling calculus beginner

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- November 14th 2009, 03:13 PMcalcbegpolar equation
Hi

Show that the polar equation r= a cos x + b sin x where ab not equal 0 represents a circle and find its center and radius

I really have no idea where to start - any ideas at all??

Thanks

Struggling calculus beginner - November 14th 2009, 03:34 PMSoroban
Hello, calcbeg!

I must assume you know these conversions:

. .

Quote:

Show that the polar equation: . .where

represents a circle and find its center and radius.

We have: .

So we have: .

Complete the square: .

Simplify: .

This is the equation of a circle: .