The area of the region enclosed by the parabola (y - 2)² = x - 1$(y - 2)^2 = x - 1$ , the line x - 2y + 4 = 0$x - 2y + 4 = 0$ and the positive coordinate axes is
The line is tangent to the parabola at y = 3$y = 3$. At y = 3$y = 3$, x = 2(3) - 4 = 2$x = 2(3) - 4 = 2$.
We need the area enclosed by the parabola, the line, and the positive coordinate axes.
Let's trace the boundary intercepts.
The line x = 2y - 4$x = 2y - 4$ cuts the y-axis (x=0$x=0$) at y=2$y=2$.
Parabola vertex is at (1, 2)$(1, 2)$. Parabola cuts y-axis (x=0$x=0$) at (y-2)² = -1$(y-2)^2 = -1$ (No real y-intercept).
So the curve (y-2)² = x-1$(y-2)^2 = x-1$ only exists for x ≥ 1$x \ge 1$.
Step 1: Setting up the Integral w.r.t y
Area Under Curve diagram for Q29 - JEE Main 2024 Evening
Because the area is bound by the positive coordinate axes, we track integration strictly in the first quadrant.
The required area is the area between the y-axis, the x-axis, the line, and the curve. Wait, the problem says "area enclosed by the parabola... line... and positive coordinate axes".
Let's integrate with respect to y$y$.
The boundary curves are x = (y-2)² + 1$x = (y-2)^2 + 1$ (which forms the rightmost boundary) and the axes.
The area bounded by the curve with y-axis is from y=0$y=0$ to y=3$y=3$ minus the triangular region cut by the line below y=2$y=2$.
The line intersects the x-axis (y=0$y=0$) at x=-4$x=-4$ and y-axis (x=0$x=0$) at y=2$y=2$.
The positive coordinate axes enforce boundaries at x ≥ 0, y ≥ 0$x \ge 0, y \ge 0$.
So the exact area is the integral of the parabola's x$x$-value from y=0$y=0$ to y=3$y=3$, minus the area of the small triangle outside the region bounded by the line x=2y-4$x=2y-4$ and the axes in the positive quadrant.
The area under the parabola (to the left towards the y-axis) from y=0$y=0$ to y=3$y=3$ is ∫₀³ xparabola dy$\int_0^3 x_{\text{parabola}} dy$.
The line bounds the region on the left from y=2$y=2$ to y=3$y=3$. Between y=0$y=0$ and y=2$y=2$, the area goes fully to the y-axis.
So, area = ∫₀³ xparabola dy - Area of Δ bounded by line and y-axis$\int_0^3 x_{\text{parabola}} dy - \text{Area of } \Delta \text{ bounded by line and y-axis}$.
The triangle bounded by x=2y-4, x=0, y=2, y=3$x=2y-4, x=0, y=2, y=3$ is: base is x=2(3)-4 = 2$x=2(3)-4 = 2$ at y=3$y=3$, height is 1$1$ (from y=2$y=2$ to y=3$y=3$). Triangle area = (1)/(2) × 2 × 1 = 1$\frac{1}{2} \times 2 \times 1 = 1$.
Hence, Enclosed Area = ∫₀³ ((y-2)² + 1) dy - 1$\int_{0}^{3} ((y-2)^2 + 1) dy - 1$.
Instead of evaluating horizontal strips with a broken left-bound, evaluate the total area mapped to the y-axis ∫₀³ x dy$\int_0^3 x dy$ and simply subtract the basic geometric triangle removed by the straight line.
For x in [0, 1]$x \in [0, 1]$, region bounded by parabola y = ± 2√(x)$y = \pm 2\sqrt{x}$.
For x in [1, √(2)]$x \in [1, \sqrt{2}]$, region bounded by ellipse y = ± √(8 - 4x²)$y = \pm \sqrt{8 - 4x^2}$.
Rewrite the numerator (2 - x²)$(2 - x^2)$ as (1 - x²) + 1$(1 - x^2) + 1$ to split the integral into two recognizable parts matching the e^x [g(x) + g'(x)]$e^x [g(x) + g'(x)]$ form.
Any integral involving e^x$e^x$ multiplied by an algebraic fraction heavily signals the use of ∫ e^x [g(x) + g'(x)] dx$\int e^x [g(x) + g'(x)] dx$. Breaking the numerator into (1-x²) + 1$(1-x^2) + 1$ is the classic key to unlock this.
Limits of π/24$\pi/24$ and 5π/24$5\pi/24$ add up to π/4$\pi/4$. When dealing with (2x)$\tan(2x)$, multiplying by 2$2$ transforms this upper/lower sum to π/2$\pi/2$, establishing the classic /$\tan/\cot$ symmetry map triggered by King's Property.
Chapter Mix
Class 12 Maths: Integrals
Q14jee_main_2026_23_january_eveningIntegration by Substitution
Let I(x) = ∫ 3dx(4x + 6)( 4x² + 8x + 3)$I(x) = \int \frac{3dx}{(4x + 6)(\sqrt{4x^{2} + 8x + 3})}$ and I(0) = √(3)4 + 20$I(0) = \frac{\sqrt{3}}{4} + 20$. If I((1)/(2)) = a√(2)b + c$I\left(\frac{1}{2}\right) = \frac{a\sqrt{2}}{b} + c$, where a, b, c in N$a, b, c \in \mathbb{N}$, (a,b) = 1$\gcd(a,b) = 1$, then a + b + c$a + b + c$ is equal to :
Comparing with a√(2)b + c$\frac{a\sqrt{2}}{b} + c$, we get a=3, b=8, c=20$a=3, b=8, c=20$.
(3,8) = 1$\gcd(3,8) = 1$, condition is met.
a + b + c = 3 + 8 + 20 = 31$$a + b + c = 3 + 8 + 20 = 31$$
Pattern Recognition
The integral format ∫ dx(ax+b)√(px²+qx+r)$\int \frac{dx}{(ax+b)\sqrt{px^2+qx+r}}$ classically demands substituting the linear outer piece as ax+b = 1/t$ax+b = 1/t$.
Chapter Mix
Class 12 Maths: Indefinite Integration
More Integral Calculus Questions — jee_main_2024_30_january_evening
Practice past-year questions one chapter at a time. Pick an exam → subject → chapter and get every PYQ for that topic — pulled together from all past papers — with the chapter's key formulas alongside.