Given: Equation of the curve 
……….(i)
= 
= 
But according to question, slope = 0
= 0
From eq. (i), 
Therefore, the point on the curve which tangent has slope 0 is 
Equation of the tangent is 
Find the equations of all lines having slope 0 which are tangent to the curve y= 1/( x^2-2x+3)
Find the equations of all lines having slope 0 which are tangent to the curve y= 1/( x^2-2x+3)