Question

How do you evaluate the definite integral `int 3 dx` from [2,7]?

Answer 1

`int_3^7 3dx = 15`

Explanation:

We want to find `int_2^7 3dx`

Using the power rule for integrating `x^n` we have:

`int_2^7 3dx = [3x^1/1]_2^7`
`:. int_2^7 3dx = [3x]_2^7`
`:. int_2^7 3dx = 3(7) - (3)(2)`
`:. int_2^7 3dx = 21- 6`
`:. int_2^7 3dx = 15`