Question

Evaluate the following definite integral:

`int_4^9 (1)/sqrt(x)*dx`

Answer 1

Let I = `int_4^9 (1)/sqrt(x)*dx`

= `int_4^9x^(-1/2)*dx`

= `[(x^(1/2))/(1/2)]_4^9`

= `2[sqrt(x)]_4^9`

= `2(sqrt(9) - sqrt(4))`

= 2 (3 – 2)

∴ I = 2