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# Some doubts watch

1. How do you integrate tanx?

now the answer would simply be [latex]\ln 4-5h[latex]
2. How do you integrate tanx?

now the answer would simply be

But why would it be wrong to multiply the numerator and denominator by -5 so that we have :

So we could factor out the -5 from the denominator and then we'd just have to integrate since this would be a case of the reverse chain rule.
But this answer seems to have that extra factor of
Where do I go wrong in approaching the problem this way?
3. Write tanx= sinx/cosx
Use the result: integral of f '(x) / f(x) = ln|f(x)| +c
4. to integrate tan(x), re-write it as sin(x)/cos(x), then use the substitution u=cos(x).

With the integral, assuming that dx is meant to be dh (i.e. a typo), you're not quite there, since the top isn't quite the derivative of the bottom. What you need to do is re-arrange to get:
.
If it isn't a typo, then essentially you just treat it as a constant, so you'd get
5. -_- this is a double post :/
and with regards to what vc94 said, don't forget the -

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