How do you find the equation of a tangent line and also normal line when given an equation of the circle and a point that is NOT on the circle ..
the problem
x^2+y^2=13 and point (-4, 7)
"find the equation of a tangent line and also normal line when given an equation of the circle and a point that is NOT on the circle"

Question

How do you find the equation of a tangent line and also normal line when given an equation of the circle and a point that is NOT on the circle .. 
the problem 
x^2+y^2=13   and point (-4, 7) 
"find the equation of a tangent line and also normal line when given an equation of the circle and a point that is NOT on the circle"

mrnood · Answer

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The line that is normal is always a diameter, and passes through the centre.

From the equation of th ecircle you know the cntre is (0,0)

so you have 2 points on the normal line so can work out its equation.

The slope of the tangent is perpendicular to the normal so its slope is -1/m

mrnood · Answer

because the point is inside the circle there is no tangent through the point...

anonymous · Answer

no the point is outside the circle ...this is how it look..

anonymous · Answer

1 sec

mrnood · Answer

ok - sorry - i see my mistake:

mrnood · Answer

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