The Sine and Cosine Functions - Dartmouth

Knowing the first derivatives of sinx and cosx, we can now find their higher derivatives. The second derivative of sinx is the first derivative of cosx, which is ¡sinx. To get the third derivative, we apply the constant multiple rule: d3 dx3 sinx = d dx (¡sinx) = ¡ d dx sinx = ¡cosx: So the third derivative of sinx is ¡cosx. ................
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