16. Let y=x2lnx. When x=e and dx=0.1, the value of dy is:
Answer is: option3
Solution:
y=x2lnx
We need to find dy when x=e and dx=0.1.
Differentiating both sides with respect to x:
dydx=ddx(x2lnx).
Using the product rule, where u=x2 and v=lnx:
ddx(x2lnx)=x2⋅ddx(lnx)+lnx⋅ddx(x2).
=x2⋅1x+lnx⋅(2x).
=x+2xlnx.
Thus,
dy=(x+2xlnx)dx.
Substituting x=e:
dy=(e+2elne)dx.
Since lne=1, this simplifies to:
dy=(e+2e⋅1)dx.
dy=(e+2e)dx.
dy=3e⋅dx.
Substituting dx=0.1:
dy=3e×0.1.
dy=3e10.
The answer is 3e10.