pi -- 3 / | | 2 | 4*x*tan (x) dx | / pi -- 4
Integral(4*x*tan(x)^2, (x, pi/4, pi/3))
The integral of a constant times a function is the constant times the integral of the function:
Use integration by parts:
Let and let .
Then .
To find :
Rewrite the integrand:
Integrate term-by-term:
The integral of a constant is the constant times the variable of integration:
The result is:
Now evaluate the sub-integral.
Integrate term-by-term:
The integral of a constant times a function is the constant times the integral of the function:
The integral of is when :
So, the result is:
Rewrite the integrand:
Let .
Then let and substitute :
The integral of a constant times a function is the constant times the integral of the function:
The integral of is .
So, the result is:
Now substitute back in:
The result is:
So, the result is:
Now simplify:
Add the constant of integration:
The answer is:
/ | | 2 2 | 4*x*tan (x) dx = C + 2*x + 4*log(cos(x)) + 4*x*(-x + tan(x)) | /
2 ___ 7*pi 4*pi*\/ 3 -pi - 2*log(4) + 2*log(2) - ----- + ---------- 72 3
=
2 ___ 7*pi 4*pi*\/ 3 -pi - 2*log(4) + 2*log(2) - ----- + ---------- 72 3
Use the examples entering the upper and lower limits of integration.