How do you find the first and second derivative of (ln(x^(2)+3))^(3)?

1 Answer
Jan 31, 2017

f'(x)=(6xln^2(x^2+3))/(x^2+3)

f''(x)=((-6x^2+18)ln^2(x^2+3) + 24x ln(x^2+3))/(x^2+3)^2

Explanation:

The first derivative is:

f'(x)=3ln^2(x^2+3)*1/(x^2+3)*2x

=(6xln^2(x^2+3))/(x^2+3)

The second derivative is:

f''(x)=((6ln^2(x^2+3) + 6x*2 ln(x^2+3)* 1/(x^2+3) * 2x)*(x^2+3)-6xln^2(x^2+3)*2x)/(x^2+3)^2

=((6ln^2(x^2+3) + (24x ln(x^2+3))/(x^2+3))*(x^2+3)-12x^2ln^2(x^2+3))/(x^2+3)^2

=(((6(x^2+3)ln^2(x^2+3) + 24x ln(x^2+3))/cancel(x^2+3))*cancel((x^2+3))-12x^2ln^2(x^2+3))/(x^2+3)^2

=(6(x^2+3)ln^2(x^2+3) + 24x ln(x^2+3)-12x^2ln^2(x^2+3))/(x^2+3)^2

=((6x^2+18-12x^2)ln^2(x^2+3) + 24x ln(x^2+3))/(x^2+3)^2

=((-6x^2+18)ln^2(x^2+3) + 24x ln(x^2+3))/(x^2+3)^2