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High School Calculus/Derivatives of Trigonometric Functions
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Formulas for Differentiation of Trigonometric Functions
In the following formulas the angle u is supposed to be expressed in circular measure.
Proofs
Proof for the derivative of
Let ,
then ;
therefore ;
In Trigonometry,
If we substitute and ,
we have
Hence
When approaches zero, likewise approaches zero, and as is in circular measure, the limit of
Hence
<p>Proof for </p>
<p>Proof for </p>
Since
<p>Proof for </p>
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