Tangent and Normal of a Circle

IMPORTANT

Tangent and Normal of a Circle: Overview

This topic covers concepts, such as, Tangent to a Circle, Equation of Tangent to a Circle, Director Circle of a Circle & Normal to a Circle etc.

Important Questions on Tangent and Normal of a Circle

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The equation of circle such that the length of the tangent to it from the points (1,0),(2,0) and ( 3,2 ) are 1, 7, 2  respectively, is

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Let ABCD be a quadrilateral with area 18, with sides AB parallel to the side CD and AB = 2CD. Let AD be perpendicular to AB and CD. If a circle is drawn inside the quadrilateral ABCD touching all the sides, then its radius is 

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Consider a circle S with centre at the origin and radius 4. Four circles A, B, C and D each with radius unity and centres -3,0, -1,0, 1,0 and 3,0 respectively are drawn. A chord PQ of the circle S touches the circle B and passes through the centre of the circle C. If the length of this chord can be expresses as x, find x.

EASY
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The lines 3x4y+4=0 and 6x8y7=0 are tangents to the same circle. The radius of this circle is

MEDIUM
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The area of the triangle formed by the positive x-axis, the normal and the tangent to the circle x2+y2=4at(1,3).

EASY
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Consider the circle C that passes through the points 1,0 and 0,1 having the smallest area. Then, the equation of the tangent to the circle C at 0,1 is

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Find the slope of the focal chords of the parabola y2=32x, which are tangents to the circle x2+y2=4 

EASY
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If the lines 3x4y+4=0 & 6x8y7=0 are tangents to a circle, then find the radius of the circle.

MEDIUM
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Find the parametric coordinates of the circle x2+y2=4 and also, find the equation of the tangent using the parametric coordinates.

MEDIUM
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The equation of normal which is at a maximum distance from-1, -1 and drawn to the circle x-12+y-22=4 is

MEDIUM
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The tangent at A(-1,2) on the circle x2+y2-4x-8y+7=0 touches the circle x2+y2+4x+6y=0 at B. Then, a point of trisection of AB is

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The length of the diameter of circle whose normal at the point (-4,3) cuts the circle again at point common to the line 5x+y=0 and x2+y2-x5+y=0 is

MEDIUM
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The tangent to the circle C1 : x2+y2-2x-1=0 at the point 2,1 cuts off a chord of length 4 from a circle C2 whose centre is 3,-2. The radius of C2 is :-

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Centres of two circles having radius 2 and 1 units respectively are 5 units apart. The area of the quadrilateral formed by joining the points of contact of external tangents drawn to two circles is equal to (in sq. units)

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The tangent to the circle C1:x2+y2-2x-1=0 at the point 2,1 cuts off a chord of length 4 from a circle C2 whose centre is 3,-2. The radius of C2 is

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For next two question please follow the same

A tangent line is drawn to a circle with unit radius at the point A and a segment AB is laid off whose length is equal to that of the arc AC, a straight line BC is drawn to intersect the extension of the diameter AO at the point P.

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The area of the trapezoid ABCD is 

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Let C be the circle concentric with the circle, 2x2+2y2-6x-10y=183 and having area 110th of the area of this circle. Then a tangent to C, parallel to the line, 3 x+y=0 makes an intercept on the y-axis, which is equal to

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From a fixed point A on the circumference of a circle of radius rAY is the perpendicular on the tangent at P of the circle, then maximum area of the triangle APY is equal to 

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The smaller of the circle touching the straight lines x-3 y=33  at 33,  0 and the line x=0, has radius r, then r3=

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Let consider a point P outside the circle with centre at C,  tangents PA and PB are drawn such that

1CA2+1PA2=116, then length of chord AB is