Home
Class 12
MATHS
Find the area enclosed between the strai...

Find the area enclosed between the straight line `y = x + 2 ` and the curve `x ^(2) =y.`

Text Solution

AI Generated Solution

The correct Answer is:
To find the area enclosed between the straight line \( y = x + 2 \) and the curve \( x^2 = y \), we can follow these steps: ### Step 1: Identify the equations The equations given are: 1. Straight line: \( y = x + 2 \) 2. Parabola: \( x^2 = y \) ### Step 2: Find the points of intersection To find the area between the two curves, we first need to find the points where they intersect. We can do this by setting the equations equal to each other. Substituting \( y \) from the line into the parabola: \[ x^2 = x + 2 \] Rearranging gives: \[ x^2 - x - 2 = 0 \] ### Step 3: Solve the quadratic equation We can solve the quadratic equation \( x^2 - x - 2 = 0 \) using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \( a = 1, b = -1, c = -2 \): \[ x = \frac{1 \pm \sqrt{(-1)^2 - 4 \cdot 1 \cdot (-2)}}{2 \cdot 1} \] \[ x = \frac{1 \pm \sqrt{1 + 8}}{2} \] \[ x = \frac{1 \pm 3}{2} \] This gives us two solutions: \[ x = 2 \quad \text{and} \quad x = -1 \] ### Step 4: Find corresponding \( y \) values Now we can find the corresponding \( y \) values for \( x = 2 \) and \( x = -1 \) using the line equation \( y = x + 2 \): - For \( x = 2 \): \[ y = 2 + 2 = 4 \quad \Rightarrow \quad (2, 4) \] - For \( x = -1 \): \[ y = -1 + 2 = 1 \quad \Rightarrow \quad (-1, 1) \] ### Step 5: Set up the integral for the area The area \( A \) between the curves from \( x = -1 \) to \( x = 2 \) can be calculated using the integral: \[ A = \int_{-1}^{2} \left( (x + 2) - x^2 \right) \, dx \] ### Step 6: Calculate the integral Now we compute the integral: \[ A = \int_{-1}^{2} (x + 2 - x^2) \, dx \] Calculating the integral: \[ = \int_{-1}^{2} (-x^2 + x + 2) \, dx \] \[ = \left[ -\frac{x^3}{3} + \frac{x^2}{2} + 2x \right]_{-1}^{2} \] ### Step 7: Evaluate the integral at the limits First, evaluate at \( x = 2 \): \[ = -\frac{2^3}{3} + \frac{2^2}{2} + 2 \cdot 2 \] \[ = -\frac{8}{3} + 2 + 4 = -\frac{8}{3} + \frac{6}{3} + \frac{12}{3} = \frac{10}{3} \] Now, evaluate at \( x = -1 \): \[ = -\frac{(-1)^3}{3} + \frac{(-1)^2}{2} + 2 \cdot (-1) \] \[ = \frac{1}{3} + \frac{1}{2} - 2 = \frac{1}{3} + \frac{3}{6} - \frac{12}{6} = \frac{1}{3} - \frac{9}{6} = \frac{1}{3} - \frac{3}{2} = \frac{1 - 4.5}{3} = -\frac{3.5}{3} = -\frac{7}{6} \] ### Step 8: Combine results Now subtract the two results: \[ A = \left( \frac{10}{3} - \left( -\frac{7}{6} \right) \right) = \frac{10}{3} + \frac{7}{6} \] Finding a common denominator (which is 6): \[ = \frac{20}{6} + \frac{7}{6} = \frac{27}{6} = \frac{9}{2} \] ### Final Answer Thus, the area enclosed between the line and the curve is: \[ \boxed{\frac{9}{2}} \text{ square units} \]
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • APPLICATIONS OF THE INTEGRALS

    MODERN PUBLICATION|Exercise OBJECTIVE TYPE QUESTIONS|20 Videos
  • APPLICATIONS OF THE INTEGRALS

    MODERN PUBLICATION|Exercise OBJECTIVE TYPE QUESTIONS -FILL IN THE BLANKS|5 Videos
  • APPLICATIONS OF THE INTEGRALS

    MODERN PUBLICATION|Exercise EXERCISE 8 (A)|28 Videos
  • APPLICATIONS OF DERIVATIVES

    MODERN PUBLICATION|Exercise CHAPTER TEST (1)|12 Videos
  • CONTINUITY AND DIFFERENTIABILITY

    MODERN PUBLICATION|Exercise CHAPTER TEST|12 Videos

Similar Questions

Explore conceptually related problems

Find the area enclosed between the circle x ^ 2 + y ^ 2 = 1 and the line x + y = 1 lying in the first quadrant.

Find the area enclosed between the circle x^2+y^2=25 and the straight line x+y=5 .

Knowledge Check

  • The area enclosed between the curves y = x^(3) and y = sqrt(x) is

    A
    `(5)/(3)` sq units
    B
    `(5)/(4)` sq units
    C
    `(5)/(12)` sq unit
    D
    `(12)/(5)` sq units
  • Area enclosed between the curve y=x^(2) and the line y = x is

    A
    `(1)/(8)`
    B
    `(1)/(6)`
    C
    `(3)/(2)`
    D
    `(1)/(7)`
  • Similar Questions

    Explore conceptually related problems

    find the area enclosed between the curves y=x^(2)-5x and y=4-2x

    The area enclosed between the curves y^(2)=x and y=|x| is

    Find the area enclosed betweent the curve y = x^(2)+3, y = 0, x = - 1, x = 2 .

    the area enclosed between y=3x and y=x^(2) is

    Find the area enclosed by the curves y= sqrtx and x= -sqrty and the circle x^(2) + y^(2) =2 above the x-axis.

    Find the area enclosed by the curve y=-x^(2) and the straight line x+y+2=0 .