How do you differentiate $cos(pi*x^2)$ ?

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Answer 1 · 2016-10-03T09:22:47

Derivative of $cos(pi*x^2)$ is $-2pixsin(pi*x^2)$

We can use Chain rule here. Let $f(x)=cos(pi*x^2)$ . Then we can write it as

$f(x)=cosg(x)$ , where $g(x)=pi*x^2$ .

Then $(df)/(dx)=(df)/(dg)xx(dg)/(dx)$

= $-sin(pi*x^2)xxpixx2x$

= $-2pixsin(pi*x^2)$

How do you differentiate cos(pi*x^2)cos(pi*x^2)?