CBSE Class 12 Mathematics Notes Chapter 8 Application of Integrals

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The application of integrals is used to calculate the area and volume of different 2-D and 3-D curves, and they have various applications in mathematics. 

  • They help us calculate the area of an arc of a circle, irregular boundaries, the volume of various curves, and the area between the two curves. 
  • Integrals include the summation of discrete data, and their applications cover basic integral concepts such as the fundamental theorem of calculus. 
  • It is used in the fields of architecture, electrical engineering, medical science and statistics.
  • In mathematics, integrals are used to calculate the area under a curve and the area of a region bounded by a curve and a line.

Application of integrals is important for class 12 students, as well as engineering mathematics. CBSE Class 12 Mathematics Notes for Chapter 8 Application of Integrals are given in the article below for easy preparation and understanding of the concepts involved.

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Application of Integrals

There are various applications of integrals. Some of them are as follows:

  • It is used to calculate the area under simple curves.
  • The concept is used to find areas enclosed by lines, arcs of circles, parabolas, and ellipses.
  • Integrals are used to find out the area between two curves.
  • It is used to find out the centroids of areas of the triangle with curved boundaries.
  • In the field of statistics, it is used to determine survey data to improve marketing plans for different companies.

Area Between the Curve and the Axis

  • The area of the region bounded by the curve y = f(x), x-axis, and the lines x = a and x = b (b > a) is given by the formula

Area = ∫ab y dx = ∫ab f(x) dx

The area between the curve and the axis

The area between the curve and the axis

  • The area of the region bounded by the curve x = Φ(y), y-axis, and the lines y = c and y = d (b > a) is given by the formula

Area = ∫cd x dy = ∫cd Φ(y) dy


Area Between Two Curve

  • The area of the region enclosed between two curves y = f(x), y = g(x), and the lines x = a, x = b is given by the formula

Area = ∫ab [f(x) - g(x)] dx

Where f(x) ≥ g (x) in [a, b]

Area Between Two Curve

Area Between Two Curve

  • If f(x) ≥ g (x) in [a, c] and f(x) ≤ g (x) in [c, b], a < c < b, then

Area = ∫ac [f(x) - g(x)] dx + ∫cb [g(x) - f(x)] dx


Method to Find Area Under Curve

  • To calculate area, first, find the equation of the curve, y = f(x), as well as its limits and axis.
  • The integration i.e. antiderivative of the curve is found.
  • The upper and lower limits are applied to the integral result, and the difference provides the area under the curve.

Area in Polar Coordinates

  • Consider the region OKM bounded by a polar curve r = f(θ) and two semi-straight lines θ = ⍺ and θ = ꞵ.
  • The area of the polar region is given by

Area = 1/2 ∫⍺ꞵ r2 dθ = 1/2 ∫⍺ꞵ f2(θ) dθ

Area in Polar Coordinates

Area in Polar Coordinates


Area Between Two Polar Curves

  • The area of a region between two polar curves r = f(θ) and r = g(θ) in the sector [⍺, ꞵ] is expressed by the integral

Area = 1/2 ∫⍺ꞵ [f2(θ) – g2(θ)] dθ

Area Between Two Polar Curves

Area Between Two Polar Curves


Some Standard Curves and their Equation

  • Straight Line:

x = a and x = – a, where a > 0

Straight Line

Straight Line

  • Circle:

x2 + y2 = a2

Circle

Circle

  • Parabola:

y2 = 4ax or y2 = – 4ax

Parabola

Parabola

  • Ellipse

x2/a2 + y2/b2 = 1

Ellipse

Ellipse

There are Some important List Of Top Mathematics Questions On Applications Of Integrals Asked In CBSE CLASS XII

CBSE CLASS XII Related Questions

  • 1.

    For events A and B, if \(P(B)=\frac{3}{5}\), \(P(A/B)=\frac{1}{2}\) and \(P(A\cup B)=\frac{4}{5}\), then \(P(A)\) is :

      • \(\frac{1}{2}\)
      • \(\frac{3}{5}\)
      • \(\frac{1}{5}\)
      • \(\frac{3}{10}\)

    • 2.

      The motion of a particle is described as \( S = 2t^{3} - 6t^{2} + 8 \). Its velocity \( \frac{dS}{dt} \), when the acceleration \( \frac{d^{2}S}{dt^{2}} \) vanishes is :

        • \( -6 \) unit/sec
        • \( 0 \) unit/sec
        • \( 18 \) unit/sec
        • \( 6 \) unit/sec

      • 3.

        For the given Linear Programming Problem, shade the feasible region on the graph and write the coordinates of the corner points.

        Minimize \(Z = 5x + 7y\)

        subject to constraints

        \[ 2x + y \geq 8 \]

        \[ x + 2y \geq 10 \]

        \[ x,\ y \geq 0. \]


          • 4.

            The value of \( \left[ \tan^{-1}(-1) + \cos^{-1}\left(-\frac{1}{2}\right) + \sin^{-1}\left(\frac{1}{2}\right) \right] \) is :

              • \( \frac{7\pi}{12} \)
              • \( \frac{5\pi}{12} \)
              • \( -\frac{5\pi}{12} \)
              • \( \frac{\pi}{3} \)

            • 5.

              For the following Linear Programming Problem, shade the feasible region on the graph and find the coordinates of its corner points :

              Minimize \(Z = 18x + 10y\)

              subject to constraints

              \[ \begin{aligned} 4x + y &\ge 20 \\ 2x + 3y &\ge 30 \\ x, y &\ge 0. \end{aligned} \]


                • 6.

                  Find the value of \(x\) if \(A = B\), where

                  \[ A = \begin{bmatrix} 6 & 3x \\ 8 & -6 \end{bmatrix} \text{ and } B = \begin{bmatrix} 6 & x^2+2 \\ 8 & x^2-5x \end{bmatrix}. \]

                    CBSE CLASS XII Previous Year Papers

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