Question

how to find equation of common tangents to two parabolas?

Answer 1

U mean 2 U shaped curves? Give me an example (describe the curves).

And by tangent u mean just touches both?

Answer 2

x^2=4ay and y^2=4ax

Answer 3

these are generic parabolas .... what you need to do is determine at what point their derivatives are equal ...

Answer 4

when you know at what point they have equal derivaties; then you know at least the slopes are parallel :)

Answer 5

if the slope between the two points matches the derivative; they would be on the same line then

Answer 6

http://www.wolframalpha.com/input/?i=plot+y^2%3D4x%2C+x^2+%3D4y%2C+x%3D-5..5