cos(x)*log(x)
Apply the product rule:
f(x)=cos(x)f{\left(x \right)} = \cos{\left(x \right)}f(x)=cos(x); to find ddxf(x)\frac{d}{d x} f{\left(x \right)}dxdf(x):
The derivative of cosine is negative sine:
g(x)=log(x)g{\left(x \right)} = \log{\left(x \right)}g(x)=log(x); to find ddxg(x)\frac{d}{d x} g{\left(x \right)}dxdg(x):
The derivative of log(x)\log{\left(x \right)}log(x) is 1x\frac{1}{x}x1.
The result is: −log(x)sin(x)+cos(x)x- \log{\left(x \right)} \sin{\left(x \right)} + \frac{\cos{\left(x \right)}}{x}−log(x)sin(x)+xcos(x)
The answer is:
cos(x) ------ - log(x)*sin(x) x
/cos(x) 2*sin(x)\ -|------ + cos(x)*log(x) + --------| | 2 x | \ x /
3*cos(x) 2*cos(x) 3*sin(x) log(x)*sin(x) - -------- + -------- + -------- x 3 2 x x