Question

高等数学题目求解答

Answer 1

a=ln 3

方法如下图所示，请作参考，祝学习愉快：

Answer 2

1/u =a/(2a+x)
lim(x->∞) [ (3a+x)/(2a+x) ]^x

=lim(x->∞) [ 1+ a/(2a+x) ]^x
=lim(u->∞) [ 1+ 1/u ]^(au-2a)
=lim(u->∞) [ 1+ 1/u ]^(au)
=e^a
=>
3=e^a
a=ln3