How do I determine the equation of the tangent to the curve [math] y=2x-x^2 [/math] that passes through point [math] (2,9) [/math]?
What will be the equation of a circle concentric with the circle [math]x^2+y^2-4x-6y-9=0[/math] and passing through the point [math](-4,-5)[/math]?