# Application of Integrals Class 12 Notes Chapter 8

## CBSE Class 12 Maths Notes Chapter 8 Application of Integrals – Related Links

### Integrals used to find the area of a curved region

Integrals are the functions which satisfy a given differential equation for finding the area of a curvy region y=f(x), the x-axis and the line x=a and x=b(b>a) is represented through this formula:

Area= $$\int_{a}^{b}ydx=\int_{a}^{b}f(x)dx$$

If curvy region is x=$$\phi (y)$$, y-axis and the line y=c, y=d is represented through this formula:

Area=$$\int_{c}^{d}xdy=\int_{c}^{d}\phi (y)dy$$

### Area Bounded By Two Curves

If the dimensions of two curves are y=f(x), y=g(x) and lines x=a and x=b is represented by the formula:

$$\int_{a}^{b}[f(x)-g(x)]dx$$, where f(x)$$\geq$$g(x) in [a,b]

If f(x)$$\geq$$g(x) in [a,c] and $$f(x)\leq g(x)$$ in [c,b], a<c<b, then area is

$$\int_{a}^{c}[f(x)-g(x)]dx+\int_{c}^{b}[g(x)-f(x)]dx$$

### Important Questions:

1. The area bounded by the curve p = y | y | , x-axis and the ordinates y = – 1 and y = 1 is given by

(A) 0

(B)1/3

(C)2/3

(D)4/3

2. Using the method of integration find the area of the region bounded by lines:
3y + z = 5, 4y – z = 6 and y – 4z + 6 = 0

3. Find the area bounded by curves {(x, y) : y ≥ $$x^{2}$$ and y = | x |}

4. Find the area of the region enclosed by the parabola $$x^{2}$$ = y, the line y = x+ 2 and the x-axis

5. Using integration find the area of a region bounded by the triangle whose vertices are (– 2, 1), (0, 4) and (4, 3).