4x4

(4+sqrt(4))*(4+sqrt(4)) = 36

arctan(degrees)[4/4] - (4+4) = 37

44 - (4+sqrt(4)) = 38

arctan(4/4) - 4 - sqrt(4) = 39

44-sqrt(4)-sqrt(4) = 40

arctan(4/4)-sqrt(4)-sqrt(4) = 41

Factorials (!) are allowed, right? Also I will assume the use of order of operations with minimum use of parenthesees.
4!+4x4+sqrt(4)=42

44-4/4=43

44+4-4=44

44+4/4=45

44+4-sqrt(4)=46

4!+4!-4/4=47

4!+4!+4-4=48

4!+4!+4/4=49

4!+4!+4-sqrt(4)=50