x^2-ky+3=0 represents a parabola whose focus is in (0,2) find k

Printable View

- Dec 17th 2011, 08:08 AMprasumFocus of parabola
x^2-ky+3=0 represents a parabola whose focus is in (0,2) find k

- Dec 17th 2011, 08:29 AMprincepsRe: parabola
- Dec 20th 2011, 10:18 AMprasumRe: parabola
can yu tell me what will be the value of k 2 ,4,6 or 3

- Dec 20th 2011, 10:46 AMSironRe: parabola
What have you tried? Princeps post tell's what you have to do, namely:

The equation of the parabola is:

$\displaystyle y=\frac{x^2+3}{k}$

Therefore we can find $\displaystyle k$ by solving the equation:

$\displaystyle \frac{-D}{4a}=2 \Rightarrow \frac{4ac-b^2}{4a}=2$

Proceed.