a maths

👨🏻‍🏫 學術台數學

[匿名]

2009-06-21 3:24 am

find the equation of tangent from the point A( 0 , 5 ) to the circle
x^2 +y^2 -2x -10y +25 = 0

plz , show all the steps clearly

更新1:

y = 0 is impossible anwser because this line is not touching the circumference of the circle do you have any other anwser?

回答 (3)

用戶7639

2009-06-21 3:41 am

✔ 最佳答案

centre of circle=(1,5)
radius of circle=√(12+52-25)
=1

∴The equation of tangent is y=0.

2009-06-20 20:15:39 補充：
∴The equation of tangent is x=0.

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yik shun

2009-06-21 7:18 pm

centre of circle is (1,5)
radius= 1

tangent ofcircle is y-5-Mx=0

absolute value ( y-5-Mx /(1+M^2)^0.5 )=1

put y=5,x=1

absolute value ( 5-5-M /(1+M^2)^0.5 )=1
M^2=1+M^2

1=0

tangent is x=0

參考: me

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用戶9112

2009-06-21 3:58 am

x=0?

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