Question #ce88a

1 Answer
Mar 10, 2017

=(1-2logxln(10))/(x^3ln(10))

Explanation:

d/(dx)(logx/x^2)

This will require the quotient rule, the power rule, and knowing the derivitave of logx.

Recall the quotient rule for finding a derivative:
d/(dx)((P(x))/(Q(x)))=((Q(x)*P'(x))-(P(x)*Q'(x)))/(Q(x)^2)

Or simply, (BT'-TB')/B^2 where T is the top function and B is the bottom function.

Also recall that d/(dx)log_a(x)=1/(xln(a)) where a is the base of the logarithm and x is the argument. You won't use this very often but you just need to memorize this.

Let's proceed:

d/(dx)(logx/x^2)

=((x^2*1/(xln(10)))-(logx*2x))/(x^2)^2

=(x^2/(xln(10))-2xlogx)/x^4

=x^2/(x^4*xln(10))-(2xlogx)/x^4

=1/(x^3ln(10))-(2logx)/x^3

Or

=(1-2logxln(10))/(x^3ln(10))