Trivial constraints correspond to the boundaries of the graph in the first quadrant.
- Since the graph is in the first quadrant, \( x \geq 0 \) and \( y \geq 0 \) are the two trivial constraints.
A battery of emf \( E \) and internal resistance \( r \) is connected to a rheostat. When a current of 2A is drawn from the battery, the potential difference across the rheostat is 5V. The potential difference becomes 4V when a current of 4A is drawn from the battery. Calculate the value of \( E \) and \( r \).