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# Integration failue of int(tan(x)^*cos(x)^3dx

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Good day everyone,

I am currently doing a math course, and one of the exercises was integrate the following: tan(x)^2*cos(x)^3. Solving this by hand returns sin(x)^3/3. Entering this on the HP Prime returns -sin(x).This does not seem correct to me. I have verified the answer with maple and a TI-Nspire, both return the correct answer.

Any ideas on this issue?

Kind regards.

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Hi!, @Willempy :

You must see, the images for Configure and Solve ...

Now, if you needed simplify, the result, is ...

Note : Conceptually, the tangent of an angle is equal to the sine divided by the cosine of that angle. If you put it that way, you'll get the result you've indicated.

Kind Regards !.
Have a nice day !.
Provost in HP Spanish Public Forum ... https://h30467.www3.hp.com/
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Hi!, @Willempy :

Too, you can solve indefinite integrate step by step and next time apply "u" substitution, from ... https://www.symbolab.com/solver/integral-calculator/%5Cint%20tan%5Cleft(x%5Cright)%5E%7B2%7D%5Ccdot%...

Kind Regards !.
Have a nice day !.
Provost in HP Spanish Public Forum ... https://h30467.www3.hp.com/
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Hey Maké,

Thanks for the clear explanation. I was able to get the correct result by hand. Indeed, when I enter tan(x) as sin(x)/cos(x) in the HP prime, the returned answer is correct. Somehow the HP prime seems to have trouble integrating tan(x) and its exponents. I will find out how and where to file a bug report.

Kind regards,

Willempy

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