To determine the number of corner points of the feasible region, let us analyze the constraints: 1. \(x \geq 0\):
This represents the region to the right of the \(y\)-axis, including the \(y\)-axis itself. 2. \(y \geq 0\):
This represents the region above the \(x\)-axis, including the \(x\)-axis itself. 3. \(x + y \geq 4\):
This represents the region above the line \(x + y = 4\).
Rearranging, \(y = 4 - x\), which has intercepts at \(x = 4\) and \(y = 4\).
The feasible region is the intersection of these constraints, which lies in the first quadrant (\(x \geq 0\), \(y \geq 0\)) and above the line \(x + y = 4\). The feasible region is unbounded but has two corner points:
Intersection of \(x + y = 4\) with \(x = 0\): \((0, 4)\), - Intersection of \(x + y = 4\) with \(y = 0\): \((4, 0)\). Hence, the number of corner points is \(2\), and the correct answer is (C).
Consider the line \[ \vec{r} = (\hat{i} - 2\hat{j} + 4\hat{k}) + \lambda(-\hat{i} + 2\hat{j} - 4\hat{k}) \]
Match List-I with List-II:
| List-I | List-II |
|---|---|
| (A) A point on the given line | (I) \(\left(-\tfrac{1}{\sqrt{21}}, \tfrac{2}{\sqrt{21}}, -\tfrac{4}{\sqrt{21}}\right)\) |
| (B) Direction ratios of the line | (II) (4, -2, -2) |
| (C) Direction cosines of the line | (III) (1, -2, 4) |
| (D) Direction ratios of a line perpendicular to given line | (IV) (-1, 2, -4) |
A carpenter needs to make a wooden cuboidal box, closed from all sides, which has a square base and fixed volume. Since he is short of the paint required to paint the box on completion, he wants the surface area to be minimum.
On the basis of the above information, answer the following questions :
Find \( \frac{dS}{dx} \).
