Jambmaths question:
If x varies directly as $\sqrt{n}$and x = 9 when n = 9, find x when n = $\frac{17}{9}$
Option A:
4
Option B:
27
Option C:
17
Option D:
$\sqrt{17}$
Jamb Maths Solution:
$\begin{align} & x\propto \sqrt{n} \\ & x=k\sqrt{n} \\ & \text{when }n=9,\text{ }x=9 \\ & 9=k\sqrt{9} \\ & 9=3k \\ & k=3 \\ & \text{When }n=\frac{17}{9} \\ & \therefore x=3\sqrt{\frac{17}{9}}=3\sqrt{\frac{17}{9}} \\ & x=\frac{3\sqrt{17}}{3}=\sqrt{17} \\\end{align}$
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