Tuesday, January 12, 2016

`int (2 - tan(theta/4)) d theta` Find the indefinite integral.

`int(2-tan(theta/4))d theta=`


Use additivity of integral: `int(f(x)pm g(x))dx=int f(x)dx pm int g(x)dx.` `int2d theta-int tan(theta/4)d theta=`


Since the first integral is easy `int 2d theta=2theta+C` we will concentrate on the second integral. To solve it we will make substitution: `u=theta/4,` `du=(d theta)/4=>d theta=4du`


`int tan(theta/4)d theta=4int tan u du=-4ln|cos u|+C`


Return the substitution.


`-4ln|cos(theta/4)|+C`  


Now we subtract the two integrals to obtain the final result.


`2theta-(-4ln|cos(theta/4)|)+C=2theta+4ln|cos(theta/4)|+C`


` `

No comments:

Post a Comment

find square roots of -1+2i

We have to find the square root of `-1+2i` i.e. `\sqrt{-1+2i}` We will find the square roots of the complex number of the form x+yi , where ...