Question

函数的连续与间断设f(x)在R上连续,且f(x)不等于0,Φ(x)在R上有定义,且有间断点,则判断“Φ(x)/f(x)必

Answer 1

let a be 间断点 of Φ(x) on R

Φ+(a)≠Φ-(a)

Φ+(a)/f(a) )≠Φ-(a)/f(a)

=> a is 间断点 of Φ(x)/f(x)