Find the equation of the plane passing through the line of intersection of the planes \(\vec r.(\hat i+\hat j+\hat k)=1 \) and \(\vec r.(2\hat i+3\hat j-\hat k)+4=0\) and parallel to x-axis.
The given planes are
\(\vec r.(\hat i+\hat j+\hat k)=1\)
⇒\(\vec r.(\hat i+\hat j+\hat k)-1=0\)
\(\vec r.(2\hat i+3\hat j-\hat k)+4=0\)
The equation of any plane passing through the intersection of these planes is
\([\vec r.(\hat i+\hat j+\hat k)-1]\) + \(λ\)\([\vec r.(2\hat i+3\hat j-\hat k)+4]\) \(= 0\)
\(\vec r.[(2λ+1)\hat i+(3λ+1)\hat j+(1-λ)\hat k]+(4λ+1)=0\) ...(1)
Its direction ratios are (2λ+1), (3λ+1) and (1-λ).
The required plane is parallel to x-axis.
Therefore, its normal is perpendicular to x-axis.
The direction ratios of x-axis are 1, 0 and 0.
\(∴1.(2+λ+1)+0(3λ+1)+0(1-λ)=0\)
⇒ \(2λ+1=0 ⇒ λ=-\frac 12\)
Substituting, \(λ=-\frac 12\) in equation (1), we obtain
⇒\(\vec r.[-\frac 12\hat j+\frac 32\hat k]+(-3)=0\)
⇒\(\vec r.(\hat j-3\hat k)+6=0\)
Therefore, its cartesian equation is \(y-3z+6=0\)
This is the equation of the required plane.
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 \(P,O,Q\).