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In this installment, I will give you the derivatives of the main trigonometric functions, namely sine, cosine and tangent. Some of you probably do not have a lot of experience with trigonometric functions, but I will not explain about these for the moment. You can read the basics on sine, cosine and tangent here:

Sine at Wolfram
Cosine at Wolfram
Tangent at Wolfram

Just stop at the point where the web pages start involving complex numbers and functions, as this is a bit more complicated and requires knowledge of complex numbers (numbers that involve the square root of negative numbers).

As for the other trigonometric functions, we will derive their derivatives later on. I am keeping those as exercises and examples.

Now, for the following functions:





where a is a constant.

Their derivatives will be:





The trigonometric function secant, or sec(x) is equal to [math]\sec {x} = \frac {1}{\cos {x}}.