{"id":8366,"date":"2021-11-20T22:56:31","date_gmt":"2021-11-20T17:26:31","guid":{"rendered":"https:\/\/mathemerize.com\/?p=8366"},"modified":"2022-01-31T18:37:03","modified_gmt":"2022-01-31T13:07:03","slug":"what-is-the-equation-of-pair-of-tangents-to-a-circle","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/what-is-the-equation-of-pair-of-tangents-to-a-circle\/","title":{"rendered":"Equation of Pair of Tangents to a Circle"},"content":{"rendered":"
Here you will learn what is the equation of pair of tangents to a circle from an external point with example.<\/p>\n
Let’s begin –<\/p>\n
Let the equation of circle S = \\(x^2\\) + \\(y^2\\) – \\(a^2\\) and P(\\(x_1,y_1\\)) is any point outside the circle. From the point we can draw two real and distinct tangent and combine equation of pair of tangents is –<\/p>\n
(\\(x^2\\) + \\(y^2\\) – \\(a^2\\))(\\({x_1}^2\\) + \\({y_1}^2\\) – \\(a^2\\)) = \\(({xx_1 + yy_1 – a^2})^2\\)<\/p>\n
or\u00a0 \\(SS_1 = T^2\\)<\/p>\n
where \\(S_1\\) = \\({x_1}^2\\) + \\({y_1}^2\\) – \\(a^2\\)<\/p>\n
and \\(T^2\\) = \\(({xx_1 + yy_1 – a^2})^2\\)<\/p><\/blockquote>\n