If y=2xlogx then dydx at x=e is
0
log2
e
e2
logy=xlogxlog2
1ydydx=log2logx−x1x(logx)2dydx=log2⋅y⋅(logx−1)(logx)2=log2⋅2e⋅(1−1)(loge)2=0