find the dervative of \((ln(x))^x\).
Then order the functions from slowest-growing to fastest-growing as x approach infinity.
\(e^x \)
\(x^x\)
\((ln(x))^x\)
\({e}^{x/2}\)
Thank you!
Possible derivation:
d/dx(log^x(x))
Express log^x(x) as a power of e: log^x(x) = e^(log(log^x(x))) = e^(x log(log(x))):
= d/dx(e^(x log(log(x))))
Using the chain rule, d/dx(e^(x log(log(x)))) = ( de^u)/( du) ( du)/( dx), where u = x log(log(x)) and ( d)/( du)(e^u) = e^u:
= (d/dx(x log(log(x)))) e^(x log(log(x)))
Express e^(x log(log(x))) as a power of log(x): e^(x log(log(x))) = e^(log(log^x(x))) = log^x(x):
= log(x)^x d/dx(x log(log(x)))
Use the product rule, d/dx(u v) = v ( du)/( dx)+u ( dv)/( dx), where u = x and v = log(log(x)):
= log(log(x)) d/dx(x)+x d/dx(log(log(x))) log^x(x)
The derivative of x is 1:
= log^x(x) (x (d/dx(log(log(x))))+1 log(log(x)))
Using the chain rule, d/dx(log(log(x))) = ( dlog(u))/( du) ( du)/( dx), where u = log(x) and ( d)/( du)(log(u)) = 1/u:
= log^x(x) (log(log(x))+(d/dx(log(x)))/(log(x)) x)
The derivative of log(x) is 1/x:
= log^x(x) (log(log(x))+(1/x x)/(log(x)))
Simplify the expression:
Answer: | = log^x(x) (1/(log(x))+log(log(x)))
y = (ln(x) )^x take the ln of both sides
ln(y) = ln [ln(x)]^x
ln (y) = x ln [ln (x) ] now.....differentiate both sides
y' / y = ln [ln (x) ] + x [ (1/x) / ln(x) ] simplify
y' / y = ln [ ln (x) ] + 1/ [ln (x) ] multiply both sides by y
y' = y [ ln [ln (x) + 1/ [ln (x) ] and substitute [ ln(x) ]^x for y
y' = [ln (x)]^x [ ln [ln(x)] + 1 / ln (x) ]
Ordering of functions from slowest growing to fastest growing as x → infinity
e^(x/2) e^x [ln (x)]^x x^x