t²x´´+tx´-x=0求它的解
t²x´´+tx´-x=0求它的解
设f(x)=x²,则=f´[f(x)]=?请问,打问号处我该填什么?
求音乐:i don´t know why
My english isn´t very good,
i don´t know anything,
I wouldn´t believe you
acute 与 sensitive 的区别是什么
that´s a
No...i don´t afraid of nothing- I´m ignorant,
Don´t explain the reason to me.
what is the differen´t between in and into
But it´s ( ).I´ll buy a( ) one.