Find the solution to the following linear programming problem (if it exists) graphically:
Maximize \( Z = x + y \)
Subject to the constraints \[ x - y \leq -1, \quad -x + y \leq 0, \quad x, y \geq 0. \]
Step 1: Plot the constraints on the graph: \[ x - y = -1 \quad \Rightarrow \quad y = x + 1, \quad -x + y = 0 \quad \Rightarrow \quad y = x. \]
Step 2: Identify the feasible region satisfying \( x, y \geq 0 \) and the constraints.
Step 3: Compute \( Z = x + y \) at each vertex of the feasible region. The maximum \( Z \) is the solution.

যদি \( \vec{a} = 4\hat{i} - \hat{j} + \hat{k} \) এবং \( \vec{b} = 2\hat{i} - 2\hat{j} + \hat{k} \) হয়, তবে \( \vec{a} + \vec{b} \) ভেক্টরের সমান্তরাল একটি একক ভেক্টর নির্ণয় কর।
যদি ভেক্টর \( \vec{\alpha} = a\hat{i} + a\hat{j} + c\hat{k}, \quad \vec{\beta} = \hat{i} + \hat{k}, \quad \vec{\gamma} = c\hat{i} + c\hat{j} + b\hat{k} \) একই সমতলে অবস্থিত (coplanar) হয়, তবে প্রমাণ কর যে \( c^2 = ab \)।
The respective values of \( |\vec{a}| \) and} \( |\vec{b}| \), if given \[ (\vec{a} - \vec{b}) \cdot (\vec{a} + \vec{b}) = 512 \quad \text{and} \quad |\vec{a}| = 3 |\vec{b}|, \] are:
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 \(P,O,Q\).