Definite Integration Question 65

Question: Find the value of $ \int _{0}^{9}{[\sqrt{x}+2]dx}, $ where [.] is the greatest integer function

[UPSEAT 2002]

Options:

A) 31

B) 22

C) 23

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

$ \int _{0}^{9}{[\sqrt{x}+2]}dx $

$ =\int_0^{1}{2dx+\int_1^{4}{3dx+\int_4^{9}{4dx}}} $

$ =2+(12-3)+(36-16) $

$ =2+9+20=31 $ .