Circle as a locus (1 Viewer)

[cookiez69]

Find the exact length of the tangent from (4,-5) to the circle x^2 + 4x + y^2 - 2y - 11 = 0

Thanks

 

[HSC2014]

Hint: Pythagoras of Samos

 

[braintic]

Find the exact length of the tangent from (4,-5) to the circle x^2 + 4x + y^2 - 2y - 11 = 0

Thanks

You should be able to complete the squares on x and y to find the centre and radius of the circle.
Find the distance between (4,-5) and the centre.
Given that the tangent is perpendicular to the radius, use Pythagoras to answer the question.
Draw a generic diagram if you don't understand.

 

[cookiez69]

You should be able to complete the squares on x and y to find the centre and radius of the circle.
Find the distance between (4,-5) and the centre.
Given that the tangent is perpendicular to the radius, use Pythagoras to answer the question.
Draw a generic diagram if you don't understand.

Got it, thanks!