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Equation of directrix of the parabola y^2=5x-4y-9

Answer»

\blue{\bold{\underline{\underline{Answer:}}}}

\green{\tt{\therefore{x+\frac{1}{4}=0}}}\\

\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}

\green{\underline \bold{<klux>GIVEN</klux>:}} \\  \tt:  \implies  {y}^{2}  = 5x - 4y - 9 \\  \\ \red{\underline \bold{To \: Find:}} \\  \tt:  \implies Eqn  \: of  \:  directrix = ?

ACCORDING to given QUESTION :

\tt:  \implies  {y}^{2}    = 5x - 4y  - 9 \\  \\ \tt:  \implies  {y}^{2}  + 4y = 5x - 9 \\  \\ \tt:  \implies  {y}^{2}  + 4y + 4 = 5x - 9 + 4 \\  \\ \tt:  \implies  {(y - 2)}^{2}  = 5x - 5 \\  \\ \tt:  \implies  {(y - 2)}^{2} = 5(x - 1) \\  \\\tt:  \implies  {(y - 2)}^{2}   = 4 \times  \frac{5}{4}(x - 1) \\  \\    \text{So, \: it \: is \: in \: the \: form \: of}\\  \\   \tt:  \implies Y^{2}  = 4aX \\  \\  \bold{Where : } \\  \tt \circ \: a =  \frac{5}{4}  \\  \\  \bold{As \: we \: know \: that} \\  \tt:  \implies Eqn \: of \: directrix  \to X =  - a \\  \\  \tt:  \implies Eqn \: of \: directrix \to x - 1 =   - \frac{5}{4}  \\  \\ \tt:  \implies Eqn \: of \: directrix \to x =   - \frac{5}{4}  + 1 \\  \\ \tt:  \implies Eqn \: of \: directrix \to x =  \frac{ - 1}{4}  \\  \\  \green{\tt:  \implies Eqn \: of \: directrix  \to x +  \frac{1}{4}  = 0}



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