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coordinate G

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coordinate G

by vipulgoyal » Fri Jun 07, 2013 4:08 am
In the figure shown, the circle has center O and radius 50, and point P has coordinates (50,0). If point Q (not shown) is on the circle, what is the length of line segment PQ ?

1) The x-coordinate of point Q is - 30.
2) The y-coordinate of point Q is - 40.

I got this qustion in two sources and in doth sources ans is differant A and E

Experts please suggest
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by srcc25anu » Fri Jun 07, 2013 10:28 am
The figure is a circle with centre at origin and we know p = (50,0)

1) The x-coordinate of point Q is - 30.
It could be A (-30,y) or B (-30,-y)
we can find the value of y if we put either of these points in the equation of the circle x^2 + y^2 = 2500, Solvinf the above eqn, we get Y = 40.
Point A becomes (-30,40) and B becomes (-30,-40)
Distance AP = BP = sqrt(80^2 + 40^2)
SUFFICIENT

2) The y-coordinate of point Q is - 40.
It could be either Point C (x,-40) or Point D (-x, -40)
CP will not be eqaul to DP (CP is much closer than DP)
hence Insufficient

Ans A
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