Use logarithmic differentiation to find the derivative of the following equation:
$$\LARGE y= (2x+1)^5(x^4-1)^6$$

Question

shamil98 · Answer

don't see how log diff would be used in this.

luigi0210 · Answer

That's what my stupid online assignment is telling me to use ._.

shamil98 · Answer

is there no y = ?
or something atleast..

shamil98 · Answer

is this just an expression?

luigi0210 · Answer

Oh, right

shamil98 · Answer

so this is y = ..... right?

luigi0210 · Answer

Yup~ http://prntscr.com/30blno

primeralph · Answer

Actually, log diff can be useful here.

shamil98 · Answer

take the natural log of both sides.
$$\ln y = \ln [(2x+1)^5(x^4-1)^6]$$
now use the log rules..
$$\ln y = \ln (2x+1)^5 + \ln (x^4-1)^6$$

anonymous · Answer

let $$y=\left( 2x+1 \right)^5\left( 5x^4-1 \right)^6$$
$$\ln y=5\ln \left( 2x+1 \right)+6\ln \left(5x^4-1  \right)$$
$$\frac{ y' }{ y }=\frac{ 5*2 }{2x+1 }+\frac{ 6*20x^3 }{5x^4-1 }$$
y'=?
replace the value of y. and get y'

shamil98 · Answer

you did pretty much all the work, but ok.

shamil98 · Answer

luigi, go review your alg 2

anonymous · Answer

sorry i wrote 5x^4 in place of x^4