Question 941
CBSE Class 11 Mathematics · Conic Sections · Parabolas
For y²=10x, give
(a)
the focus
(b)
axis
(c)
directrix
(d)
latus-rectum length.
Solution to Question 941
Complete workingTranslate every condition into an equation and retain exact values throughout the conic calculation.
\[\begin{aligned}4a &= 10\Rightarrow a\\&= \frac52\end{aligned}\]
\[\begin{aligned}F &= (\tfrac52,0),\quad\text{axis }y\\&= 0\end{aligned}\]
\[\begin{aligned}\text{directrix }x &= -\frac52,\quad\ell\\&= 10\end{aligned}\]
The last line satisfies the original conditions and supplies every requested part.
Final answers by part
(a)
\[F=(\tfrac52,0)
(b)
\ y=0
(c)
\ x=-\tfrac52
(d)
\ \ell=10\]