EquationEquation GraphGraph FocusFocus Length of LRLength\space of\space LR Equation of DirectrixEquation\space of\space Directrix Equation of AxisEquation\space of\space Axis
y2=4axy^2=4ax (a,0)(a,0) 4a4a x=ax=-a y=0y=0
y2=4axy^2=-4ax (a,0)(-a,0) 4a4a x=ax=a y=0y=0
x2=4ayx^2=4ay (0,a)(0,a) 4a4a y=ay=-a x=0x=0
x2=4ayx^2=-4ay (0,a)(0,-a) 4a4a y=ay=a x=0x=0

Equations of Tangent of all Parabolas in slope form

Equations ofEquations\space of
ParabolaParabola
Point of contact inPoint\space of\space contact\space in
 terms of slope(m)\space terms\space of\space slope(m)
Equation of tangent inEquation\space of\space tangent\space in
 terms of slope(m)\space terms\space of\space slope(m)
Condition of TangencyCondition\space of\space Tangency

y2=4axy^2=4ax (am2,2am)(\frac{a}{m^2},\frac{2a}{m}) y=mx+amy=mx+\frac{a}{m} c=amc=\frac{a}{m}
y2=4axy^2=-4ax (am2,2am)(-\frac{a}{m^2},-\frac{2a}{m}) y=mxamy=mx-\frac{a}{m} c=amc=-\frac{a}{m}
x2=4ayx^2=4ay (2am,am2)(2am,am^2) y=mxam2y=mx-am^2 c=am2c=-am^2
x2=4ayx^2=-4ay (2am,am2)(-2am,am^2) y=mx+am2y=mx+am^2 c=am2c=am^2

Equations of Normal of all Parabolas in slope form

Equations ofEquations\space of
ParabolaParabola
Point of contact inPoint\space of\space contact\space in
 terms of slope(m)\space terms\space of\space slope(m)
Equation of normal inEquation\space of\space normal\space in
 terms of slope(m)\space terms\space of\space slope(m)
Condition of NormalityCondition\space of\space Normality

y2=4axy^2=4ax (am2,2am)(am^2,-2am) y=mx2amam3y=mx-2am-am^3 c=2amam3c=-2am-am^3
y2=4axy^2=-4ax (am2,2am)(am^2,2am) y=mx+2am+am3y=mx+2am+am^3 c=2am+am3c=2am+am^3
x2=4ayx^2=4ay (2am,am2)(-\frac{2a}{m},\frac{a}{m^2}) y=mx+2a+am2y=mx+2a+\frac{a}{m^2} c=2a+am2c=2a+\frac{a}{m^2}
x2=4ayx^2=-4ay (2am,am2)(\frac{2a}{m},-\frac{a}{m^2}) y=mx2aam2y=mx-2a-\frac{a}{m^2} c=2aam2c=-2a-\frac{a}{m^2}

Director Circle of all Parabolas

Equations of ParabolaEquations\space of\space Parabola Equation of Director CircleEquation\space of\space Director\space Circle
y2=4axy^2=4ax x+a =0x\,+a\space=\,0
y2=4axy^2=-4ax xa =0x\,-a\space=\,0
x2=4ayx^2=4ay y+a =0y\,+a\space=\,0
x2=4ayx^2=-4ay ya =0y\,-a\space=\,0