# Circle Equations

## Recognise and use the equation of a circle with centre at the origin and the equation of a tangent to a circle.

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This is level 2: equations of tangents to circles.

 1) Find the gradient of the radius of the circle $$x^2+y^2=10$$ that meets the circumference at (1,3) 2) Find the gradient of the tangent of the circle $$x^2+y^2=10$$ that touches the circle at (3,1) 3) One of the following options is the equation of a tangent to the circle $$x^2+y^2=16$$. Type in the letter of the correct option.a) $$y=16$$b) $$y=4x$$c) $$y=-4$$d) $$x=8$$ 4) One of the following options is the equation of a tangent to the circle $$x^2+y^2=29$$ at the point (5,2). Type in the letter of the correct option.a) $$y=5x-29$$b) $$2y+5x=29$$c) $$y=x+29$$d) $$y=29x$$ 5) One of the following options is the equation of a tangent to the circle $$x^2+y^2=25$$ at the point (4,3). Type in the letter of the correct option.a) $$3y+4x=25$$b) $$2y+5x=3$$c) $$3y+4x=5$$d) $$y=12x$$ 6) By first finding the equation of the tangent to the circle $$x^2+y^2=40$$ which passes through the point (2,6) determine the x-coordinate of the point where this tangent crosses the x-axis. 7) By first finding the equation of the tangent to the circle $$x^2+y^2=13$$ which passes through the point (-2,3) determine the x-coordinate of the point where this tangent crosses the x-axis. 8) By first finding the equation of the tangent to the circle $$2x^2+2y^2=82$$ which passes through the point (4,5) determine the y-coordinate of the point where this tangent crosses the y-axis.
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This is Circle Equations level 2. You can also try:
Level 1

## Instructions

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## Description of Levels

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Level 1 - Equations of circles

Level 2 - Equations of tangents to circles

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