BITSAT 2024Paper 1
- Exam
- BITSAT
- Year
- 2024
- Paper
- Paper 1
- Subject
- Mathematics
- Chapter
- Area Under Curves
BITSAT 2024 · Paper 1 · Mathematics · Area Under Curves
If the area bounded by the curves y=a x^2 and x=a y^2,(a>0) is 3 sq...
If the area bounded by the curves and is 3 sq units, then the value of is

Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
We have given, ....(i) ......(ii)
Put the value of by Eq. (i) in Eq. (ii), we get
When, and
Here, points of intersection of curves are (0,0) and \left(\frac{1}{a}, \frac{1}{a}\right)\therefore \quadA=\int_{x=a}^{x=b}\left[f_2(x)-f_1(x)\right] d x3=\int_0^{1 / a}\left(\frac{\sqrt{x}}{\sqrt{a}}-a x^2\right) d x3=\left[\frac{1}{\sqrt{a}} \times \frac{2}{3} x^{3 / 2}-\frac{a x^3}{3}\right]_0^{1 / a}3=\frac{2}{3 \sqrt{a}}\left[\left(\frac{1}{a}\right)^{3 / 2}\right]-\frac{a}{3}\left[\left(\frac{1}{a}\right)^3\right]3=\frac{2}{3 \sqrt{a}} \times \frac{1}{a \sqrt{a}}-\frac{a}{3} \times \frac{1}{a^3}3=\frac{2}{3 a^2}-\frac{1}{3 a^2} \Rightarrow 3=\frac{2-1}{3 a^2} \Rightarrow 9 a^2=1a^2=\frac{1}{9} \Rightarrow a=\frac{1}{3}
When, and
Here, points of intersection of curves are (0,0) and \left(\frac{1}{a}, \frac{1}{a}\right)\therefore \quadA=\int_{x=a}^{x=b}\left[f_2(x)-f_1(x)\right] d x3=\int_0^{1 / a}\left(\frac{\sqrt{x}}{\sqrt{a}}-a x^2\right) d x3=\left[\frac{1}{\sqrt{a}} \times \frac{2}{3} x^{3 / 2}-\frac{a x^3}{3}\right]_0^{1 / a}3=\frac{2}{3 \sqrt{a}}\left[\left(\frac{1}{a}\right)^{3 / 2}\right]-\frac{a}{3}\left[\left(\frac{1}{a}\right)^3\right]3=\frac{2}{3 \sqrt{a}} \times \frac{1}{a \sqrt{a}}-\frac{a}{3} \times \frac{1}{a^3}3=\frac{2}{3 a^2}-\frac{1}{3 a^2} \Rightarrow 3=\frac{2-1}{3 a^2} \Rightarrow 9 a^2=1a^2=\frac{1}{9} \Rightarrow a=\frac{1}{3}