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Integral tan(x)?

Date: 6/10/96 at 10:49:10
From: Anonymous
Subject: Integral tan(x)?

What is the antiderivative of the function tan(x)?

Date: 6/10/96 at 11:18:24
From: Doctor Anthony
Subject: Re: Integral tan(x)?

Write tan(x) = sin(x)/cos(x)

So INT[sin(x)/cos(x).dx] is what we require.  

Put cos(x) = u  then -sin(x).dx = du

So INT[-du/u] = -ln(u) + const

              = -ln(cos(x)) + const

              = ln(sec(x)) + const.

-Doctor Anthony,  The Math Forum
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Associated Topics:
High School Calculus

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