The area (in sq. units) of the region bounded by the curve \(x = y^{2}\), the y-axis and the lines y = 3 and y = 4 is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(\displaystyle\frac{37}{3}\)
The region lies between the y-axis (x = 0) and the curve \(x = y^{2}\), from y = 3 to y = 4. So the area is found by integrating x with respect to y:
\( \displaystyle A = \int_{3}^{4} y^{2}\,dy \)
\( \displaystyle = \left[\frac{y^{3}}{3}\right]_{3}^{4} \)
\( \displaystyle = \frac{64-27}{3} = \frac{37}{3} \)
Why the other options are incorrect
Option (2) \(\displaystyle\frac{47}{3}\) — Incorrect. The integral is \(\frac{64-27}{3} = \frac{37}{3}\), not \(\frac{47}{3}\).
Option (3) 7 — Incorrect. This is \(4^{2} - 3^{2}\), the change in \(y^{2}\), not its integral.
Option (4) \(\displaystyle\frac{91}{3}\) — Incorrect. This adds the two values, \(\frac{64+27}{3}\), instead of subtracting the lower limit value.