[?] Calculate a definite integral?

Questions
1

Why the output of a definite integral is in between braces key

Braces.png
Braces.png734×133 37.4 KB

What is the meaning of this?, it suppose to show an algebraic expression in function of the integers limits

2

Works fine :slight_smile:

Integrate[7/4 r^3 Cos[17/100 + (4 p)/39]^2 Cos[p/4] Cos[1/10 (33/20 + p)]^2, {r, a, b}, {p, 0, 2 Pi}, {t, 0, 2 Pi}]

(* 2730 (-(a^4/4) + b^4/4) \[Pi] (1/780 + (5 (-1 + Sqrt[5]) Cos[33/100])/
   5616 + (195 Cos[1/100] Cos[(2 \[Pi])/195])/304072 + (
   195 Cos[67/100] Cos[(37 \[Pi])/195])/494648 + Sin[1/100]/76018 + 
   1/351 Sin[33/100] - (5 Sqrt[1/2 (5 + Sqrt[5])] Sin[33/100])/
   2808 + (8 Sin[17/50])/2485 - (39 Cos[(7 \[Pi])/78] Sin[17/50])/
   9940 - (79 Sin[67/100])/123662 - (
   195 Sin[1/100] Sin[(2 \[Pi])/195])/304072 + (
   39 Cos[17/50] Sin[(7 \[Pi])/78])/9940 + (
   195 Sin[67/100] Sin[(37 \[Pi])/195])/494648) *)

Clear the Kernel and then caluculate integral:

 ClearAll["Global`*"]; Remove["Global`*"]
3

Please post code rather than an image (it is not possible to cut and paste an image).

4

It was the kernel, thank you!

5

I´m sorry i´m new on this.