If y=(x^3)ln(x^3) then dy/dx=?

2 Answers
Apr 9, 2018

y=(x^3)ln(x^3)

Applying product rule,

dy/dx=(x^3)'ln(x^3) + (x^3)[ln(x^3)]'

dy/dx = 3x^2ln(x^3) +cancel x^3*(1/cancelx^3*3x^2)

dy/dx = 3x^2ln(x^3) + 3x^2

dy/dx = 3x^2(ln(x^3) + 1)

Apr 9, 2018

Use ln(x^3) = 3lnx to write:

y = 3x^3lnx

Now use the product rule to differentiate.

y' = 9x^2lnx + 3x^3 * 1/x And simplify

y' 9x^2lnx+3x^2 = 3x^2(1+3lnx)