The co-ordinates of the focus of the parabola described parametrically by $x=5 t^2+2, y=10 t+4$ are

• Correct answer
  A

  $(7,4)$
• B

  $(3,4)$
• C

  $(3,-4)$
• D

  $(-7,4)$

Solution

Hints: $\mathrm{x}=5 \mathrm{t}^2+2 ; \mathrm{y}=10 \mathrm{t}+4,\left(\frac{y-4}{10}\right)^2=\left(\frac{x-2}{5}\right)$ or, $(\mathrm{y}-4)^2=20(\mathrm{x}-2)$

Hence, the correct answer is option: 'A'.