Question

FInd the equations of the tangent and normal to the
curve x^2 + y^2 + 3xy -11 = 0
at the Point x = l,Y - 2..
How to proceed with this? This seems ellipse but what to do of 3xy in the equation? Help please.

Answer 1

use implicit differentiation
2x + 2ydy/dx + 3xdy/dx + 3y =0
now find dy/dx in terms of x and y

Answer 2

basically, for the given conic , differentiate to find the slope of tangent at the point (1,-2) so u hav the tangent equation....now once u hav tangent slope,m, then the normal slope is -1/m . go ahead and solve :)

Answer 3

don't rely on formulas every where...please. they r derived from this cocept i explained :)

Answer 4

now plug in x as 1 y as 2 to get the slope of tangent...lets say m
the tangent is
(y-2)/(x-1) = m
solve:)

Answer 5

got it?

Answer 6

Yeah, formulae are very confusing.They vary from text to text.Thanks for the idea.

Answer 7

dont ratto formulae..it gets u nowhere in maths

Answer 8

Yeah, but formulae save time.

Answer 9

in the paper they ask those qstns which rnt based on formulae...ull get stumped...jst advising frm experience..

Answer 10

yeah, yeah,thanks for advice.Not arguing with you.

Answer 11

haan haan..no worries...always welcome

Answer 12

thanks everybody.