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2 votes
Question 8
Find the indefinite integral.
csc(4x) dx.

Question 8 Find the indefinite integral. csc(4x) dx.-example-1
User Sumer
by
6.5k points

2 Answers

1 vote

Answer:

Option C is correct.

Explanation:

Your solution is correct. Given the integral
\int \csc \left(4x\right)dx, let y = 4x, du = 4dx, respectively
(1)/(4)du = dx. Rewrite the given using these values of u and du.


(du)/(dx) = 4 / 1 = 4,


\int csc(u)(1)/(4) du - let us combine csc( u ) and 1 / 4,


\int csc(u) / 4 * du - as 1 / 4 is a constant with respect to u, we can move it out of the integral,


(1)/(4) \int csc(u)du - the integral of csc( u ) with respect to u is present in the form

"
In(|csc(u) - cot(u)|) . " Therefore,


(1)/(4) ( In(|csc(u) - cot(u)|) + C ) - replace all occurrences of u with 4x to receive the third solution. It can also be written as "
(1)/(4) ( In(|csc(4x) - cot(4x)|) + C ), but only that your move the negative sign to the left of the integral.

User Tomas Kirda
by
7.0k points
3 votes
The correct answer is C. Using u-substitution: u=4x, du/dx=4, dx=du/4. So now we have to take the indefinite integral of (1/4)*csc(u). Which is (-1/4)ln|csc(u)+cot(u)|. Finally plug in 4x for u, which gives C, or the third option.
User Thomas Bolander
by
6.7k points
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