could someone explain how sine^2 +cos^2 =1 can prove (x-3)^2+ (y-5)^2 =4.

Thank You

Keith

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- Feb 25th 2007, 09:55 AMkcsteventrig idenity
could someone explain how sine^2 +cos^2 =1 can prove (x-3)^2+ (y-5)^2 =4.

Thank You

Keith - Feb 25th 2007, 10:02 AMPlato
Are you once again thinking about parametric presentations of the circle (x-3)^2+ (y-5)^2 =4? If so they are: x(t)=2cos(t)+3 & y(t)=2sin(t)+5. Just substitute in the original and you will see how it works.