The equation of line passing through point (5,1) and tangent to circle "x square + y square = 25" is -

The equation of line passing through point (5,1) and tangent to circle "x square + y square = 25" is -

X = 5 is one of the tangents perpendicular to the X axis
Let another tangent not perpendicular to the X axis be y = K (X-5) + 1
If the distance of the tangent line of the center of the circle (0,0) is radius 5, the equation is as follows:
5²=|-5k+1|²/(1+k²)
That is 25 + 25K & # 178; = 25K & # 178; - 10k + 1
K = - 12 / 5
So the other tangent is y = - (12 / 5) (X-5) + 1 = - 12x / 5 + 13
So there are two tangents: x = 5, or y = - 12x / 5 + 13