Logarithmic Differentiation for y=x^{sin(x)}

crybllrd
Messages
120
Reaction score
0

Homework Statement



Find y' using logarithmic differentiation if y=x^{sin(x)}

Homework Equations


The Attempt at a Solution



lny=sin(x)ln(x)

\frac{1}{y}(y')=sin(x)(\frac{1}{x})+ln(x)\cdot cos(x)

(y')=[sin(x)(\frac{1}{x})+ln(x)\cdot cos(x)]y

Did I do this one properly?
Thanks in advance.
 
Physics news on Phys.org
It looks fine to me.
 
Looks good to me.

Depending on what the question wants, you may want to sub in x^{\sin(x)} for y in your final answer. (LaTeX tip: you can use \sin, \cos, and \ln to get "normal" text for sin, cos, ln, etc.)
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top