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Grade 11Analytical Geometry

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A common tangent drawn to a circle x2+y2=c2 and a parabola y2=4ax.If the angle which this tangent makes with twe x axis is pi/4 then the relationship between c and a is?

Profile image of Vaibhav
9 Years agoGrade 11
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1 Answer

Profile image of Nishant Vora
9 Years ago
Let assume the eqn of tangent is y = mx + a/m

tangent makes 45 deg with x axis hence slope will be 1 => m =1

henceeqn of tangent is y = x + a

and this line tangent to circle also so perpendicular distance from center to tangent equals radius

So,

a/root2 = c

hence 2c^2 = a^2

Thank You!