f'(x)=e^(kx)+kxe^(kx)=(1+kx)e^(kx).
(1)f(0)=0,f'(0)=1,所求切线方程为:y=x.
(2)若k0,f(x)递增.
此时,f(x)的单调递减区间是(-无穷,-1/k),单调递增区间是(-1/k,+无穷).
(3)若k=1,则-1
f'(x)=e^(kx)+kxe^(kx)=(1+kx)e^(kx).
(1)f(0)=0,f'(0)=1,所求切线方程为:y=x.
(2)若k0,f(x)递增.
此时,f(x)的单调递减区间是(-无穷,-1/k),单调递增区间是(-1/k,+无穷).
(3)若k=1,则-1