................x ၏ခ်ည္းကပ္တန္ဖိုး x'တြင္ f(x)
၏စည္းသတ္တန္ဖိုးဆိုသည္မွာခ်ည္းကပ္တန္ဖိုး(x')၏မီွခ်က္တန္ဖိုး f(x')
ပင္ျဖစ္သည္။
သေကၤတအားျဖင့္
..............................lim f(x)=f(x') ျဖစ္ပါသည္။
.............................x->x'
Example.1
lim 3x
x->2
Let f(x)=3x
x=4,f(4)=12
x=3,f(3)=9
x=2.5,f(2.5)=7.5
x=2.25,f(2.25)=6.75
x=2.01,f(2.01)=6.03
x=2.001,f(2.001)=6.003
:
:
:
and so on
x->2 => f(x)->6
Therefore
..........lim 3x=6
.........x->2
Example.2
..........lim 5=?
x->3
x=5, f(5)=5…
x=4, f(4)=5
x=3.5, f(3.5)=5
x=3.01, f(3.01)=5
:
:
:
and so on
x->3 => f(x)=5
Therefore,
lim 5=5
x->3
Identity
lim C=C
x->k
proof
lim C=lim C.f(x)=C.f(k)=C [f(x)=f(k)=1]
x->k x->k
[In above example 2,f(x)=C]