SOLUTION: A tangent line only touches the circle at one point, and is perpendicular to the line that connects the centre of the circle and the touching point. For circle x^2 + y^2 = 5, deter

Algebra ->  Length-and-distance -> SOLUTION: A tangent line only touches the circle at one point, and is perpendicular to the line that connects the centre of the circle and the touching point. For circle x^2 + y^2 = 5, deter      Log On


   

Question 1124596: A tangent line only touches the circle at one point, and is perpendicular to the line that connects the centre of the circle and the touching point. For circle x^2 + y^2 = 5, determine the equation of the tangent line that passes through M(2,1).
Answer by Alan3354(69443) About Me  (Show Source):
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For circle x^2 + y^2 = 5, determine the equation of the tangent line that passes through M(2,1).
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The slope of the tangent at any point of a circle with its center at the Origin is
m = -x/y
---> m = -2
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--> Find an eqn of a line thru (2,1) with a slope of -2