Equation of tangent to curve at point P(x_{1}, y_{1}) 
or T = 0 
Equation of tangent to curve at point whose eccentric angle is Ï† 
tan Ï† = 1 
Equation of tangent to curve whose slope is m 
y = mx Â± 
Equation of normal to curve at point P(x_{1}, y_{1}) 

Equation of normal to curve at point whose eccentric angle is Ï† 

Points of contact when y = mx + ctouches the curve 

Equation of chord contact w.r.t. any point P(x_{1}, y_{1}) 

Equation of chord PQ which bisected at point R(x_{1}, y_{1}) 

Pair of tangents from point P(x_{1},y_{1}) 
or T^{2} = SS_{1} 
Locus of point of intersection of tangents which are perpendicular or equation of director circle 
x^{2} + y^{2} = a^{2} â€“ b^{2} (a > b) 
Equation of the chord joining the points P(Ï†_{1}) and Q(Ï†_{2}) 
