Apply the quotient rule, which is:
dxdg(x)f(x)=g2(x)−f(x)dxdg(x)+g(x)dxdf(x)
f(x)=sin(log(x)3) and g(x)=cos(log(x)3).
To find dxdf(x):
-
Let u=log(x)3.
-
The derivative of sine is cosine:
dudsin(u)=cos(u)
-
Then, apply the chain rule. Multiply by dxdlog(x)3:
-
Let u=log(x).
-
Apply the power rule: u3 goes to 3u2
-
Then, apply the chain rule. Multiply by dxdlog(x):
-
The derivative of log(x) is x1.
The result of the chain rule is:
x3log(x)2
The result of the chain rule is:
x3log(x)2cos(log(x)3)
To find dxdg(x):
-
Let u=log(x)3.
-
The derivative of cosine is negative sine:
dudcos(u)=−sin(u)
-
Then, apply the chain rule. Multiply by dxdlog(x)3:
-
Let u=log(x).
-
Apply the power rule: u3 goes to 3u2
-
Then, apply the chain rule. Multiply by dxdlog(x):
-
The derivative of log(x) is x1.
The result of the chain rule is:
x3log(x)2
The result of the chain rule is:
−x3log(x)2sin(log(x)3)
Now plug in to the quotient rule:
cos2(log(x)3)x3log(x)2sin2(log(x)3)+x3log(x)2cos2(log(x)3)