How do you differentiate y=lnx2?

3 Answers
Mar 4, 2016

dydx=2x

Explanation:

Applying the chain rule, along with the derivatives ddxln(x)=1x and ddxx2=2x, we have

dydx=ddxln(x2)

=1x2(ddxx2)

=1x2(2x)

=2x

Mar 4, 2016

2x

Explanation:

Alternatively, we can simplify ln(x2)=2ln(x) from the outset, using the rule that log(ab)=blog(a).

Since ddxln(x)=1x, we see the constant can be brought from the differentiation in ddx2ln(x)=2ddxln(x)=2x.

Mar 4, 2016

2x

Explanation:

Just to show the versatility of calculus, we can solve this problem through implicit differentiation.

Raise both side to the power of e.

y=ln(x2)

ey=eln(x2)

ey=x2

Differentiate both sides with respect to x. The left side will require the chain rule.

ey(dydx)=2x

dydx=2xey

Recall that ey=x2.

dydx=2xx2=2x