Of the following, which group of constraints represents the feasible region given below?
\( x + 2y \geq 76, 2x + y \geq 104, x, y \geq 0 \)
Step 1: Analyze the boundary lines
The constraints for the shaded region are based on the lines:
\[ x + 2y = 76 \quad {and} \quad 2x + y = 104. \]
From the diagram:
- The region is above the line \( x + 2y = 76 \), so \( x + 2y \geq 76 \).
- The region is below the line \( 2x + y = 104 \), so \( 2x + y \leq 104 \).
- The region is in the first quadrant, so \( x \geq 0 \) and \( y \geq 0 \).
Step 2: Verify each option
Option (C) correctly represents the constraints as:
\[ x + 2y \geq 76, \quad 2x + y \leq 104, \quad x, y \geq 0. \]
Step 3: Conclude the result
The group of constraints representing the feasible region is:
\[ x + 2y \geq 76, \quad 2x + y \leq 104, \quad x, y \geq 0. \]
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 \( \frac{dS}{dx} \).
Find the interval in which $f(x) = x + \frac{1}{x}$ is always increasing, $x \neq 0$.