The line parallel to x-axis and passing through the origin is x-axis itself.
Let A be a point on x-axis.
Therefore, the coordinates of A are given by (a, 0, 0, 0), where a∈R.
Direction ratios of OA are (a-0)=a,0,0
The equation of OA is given by,
\(\frac{x-0}{a}\)=\(\frac{y-0}{0}\)=\(\frac{z-0}{0}\)
⇒\(\frac{x}{1}\)=\(\frac{y}{0}\)=\(\frac{z}{0}\)=a
Thus, the equation of line parallel to x-axis and passing through the origin is \(\frac{x}{1}\)=\(\frac{y}{0}\)=\(\frac{z}{0}\)
A racing track is built around an elliptical ground whose equation is given by \[ 9x^2 + 16y^2 = 144 \] The width of the track is \(3\) m as shown. Based on the given information answer the following: 
(i) Express \(y\) as a function of \(x\) from the given equation of ellipse.
(ii) Integrate the function obtained in (i) with respect to \(x\).
(iii)(a) Find the area of the region enclosed within the elliptical ground excluding the track using integration.
OR
(iii)(b) Write the coordinates of the points \(P\) and \(Q\) where the outer edge of the track cuts \(x\)-axis and \(y\)-axis in first quadrant and find the area of triangle formed by points \(P,O,Q\).