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Abhisar
 one year ago
Prove that length of the chord P1P2 is 2RCos \(\theta\)
Abhisar
 one year ago
Prove that length of the chord P1P2 is 2RCos \(\theta\)

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welshfella
 one year ago
Best ResponseYou've already chosen the best response.0dw:1437471838416:dw

welshfella
 one year ago
Best ResponseYou've already chosen the best response.0By the Cosine Rule r^2 =r^2 +p1p2 ^2  2r(p1p2)cos theta solve for p1p2

welshfella
 one year ago
Best ResponseYou've already chosen the best response.0p1p2 ^2  2r(p1p2)cos theta r^2  r^2 = 0 p1p2(p1p2  2r cos theta) = 0 (p1p2  2r cos theta) = 0 or pip2 = 0 p1p2 = 2r cos theta

welshfella
 one year ago
Best ResponseYou've already chosen the best response.0* correction to first line: p1p2 ^2  2r(p1p2)cos theta = r^2  r^2 = 0

Loser66
 one year ago
Best ResponseYou've already chosen the best response.2O is middle point of \(P_1P_2\), and \(P_1C= R\) Hence \(CO\perp P_1P_2\), that gives us \(cos (\theta)=\dfrac{P_1O}{R}\rightarrow 2P_1O=P_1P_2= 2Rcos(\theta)\)

Abhisar
 one year ago
Best ResponseYou've already chosen the best response.0Thank you very much @welshfella and @loser66

Loser66
 one year ago
Best ResponseYou've already chosen the best response.2@Astrophysics Make question here, please.

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.0Everything checks out, I had a similar method, but yours is quicker, nice job! :P
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