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Help me answer this indefinite integral question please

Help me answer this indefinite integral question please-example-1
User KeesDijk
by
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1 Answer

7 votes

Answer:

See below.

Explanation:

(i)
\int (3)/(x) \, dx

1) Use Constant Factor Rule:
\int cf(x) \, dx=c\int f(x).


3\int (1)/(x) \, dx

2) The derivative of
ln{x} is
(1)/(x).


3\text{ln}x

3) Add constant.


3\text{ln}x+C

------------------------------------------------------------------

(ii)
\int(1)/(4x) dx

1) Use Constant Factor Rule:
\int cf(x) \, dx=c\int f(x).


(1)/(4) \int(1)/(x) dx

2) The derivative of
\text{ln}x is
(1)/(x).


\frac{\text{ln}x}{4}

3) Add constant.


\frac{\text{ln}x}{4} +C

----------------------------------------------------------------------

(iii)
\int(1)/(x-5) dx

1) Use Integration by Substitution.

Let
u=x-5,du=dx

2) Using
u and
du above, rewrite
\int(1)/(x-5) dx.


\int(1)/(u) du

3) Substitute
u=x-5 back into the original integral.


\text{ln}(x-5)

4) Add constant.


\text{ln}(x-5)+C

------------------------------

Thanks.

User Arshad Rehmani
by
5.0k points