How do you evaluate the definite integral int (3sqrtx) dx from [1,3]?

2 Answers
Dec 12, 2016

The answer is =2(3sqrt3-1)=8.39

Explanation:

We use

intx^ndx=x^(n+1)/(n+1)+C (n!=-1)

So,

int_1^3 3sqrtxdx=3int_1^3x^(1/2)dx

=3 [x^(3/2) /(3/2) ] _1^3

=2 [3^(3/2)-1]

=2(3sqrt3-1)

=8.39

Dec 12, 2016

int_1^3 3sqrt(x)dx = 2 (sqrt(27) -1)

Explanation:

int_1^3 3sqrt(x)dx = 3 int_1^3 x^(1/2)dx =3 [ x^(3/2)/(3/2)]_1^3 = 2 [ x^(3/2)]_1^3 = 2 (sqrt(27) -1)