Showing posts with label special integrals. Show all posts
Showing posts with label special integrals. Show all posts

Friday, May 22, 2009

Calculating Area by Integration

Integration is an important concept in calculus where for a given relations and functions, x is a real variable and for the interval, integral will be calculated. Here is one such example.

Topic : Finding an area of the given function by Integration
Definite and indefinite integrals are the two special integrals.

Problem : Given function y = x2 - 5x - 6. Find the area by Integration when function is enclosed by x - axis at the interval (0,4)

Solution :

The area is given by the formula

area = ab f(x) dx = ab y dx

given y = x2 - 5x - 6
enclosed by x - axis, x = 0 and x = 4
Therefore,

Area = x = 4x = 0 y dx

= 04 (x2 - 5x - 6) dx

= [x3/3 - 5x2/2 - 6x x=0]x=4

= 43/3 - 5(4)2/2 - 6(4)

= 64/3 - 80/2 - 24

= (128 - 240 - 144)/6

= (128 - 384)/6

= -256/6


So area is approximately 42.5 squnits

If you have any queries related to the above problem or the concept please feel free to contact calculus help.