1. The problem statement, all variables and given/known data What is Lim (1+x2)/(4-x) as x approaches 4 from the left? Prove using the definition. 2. Relevant equations 3. The attempt at a solution Well x≠4. Function approaches positive infinity as x approaches 4 from the left side. Let m>0 and 0<x<4. Then (1+x2)/(4-x) > x2/(4-x) > x/(4-x) > m when x...here I am stuck. So basically I need to show that if x>xm then (1+x2)/(4-x) >m? But at some point the same function approaches negative infinity so do a choose xm=(something, 4)?