Limit Rules
Here is a handout on limit rules:
Calculus I Carrie Diaz Eaton, Unity College
Special limits of sequences rules
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When the base changes:
Discrete For an=n-k=1nk, k>0, thennan=0
Continuous or f(x) = x-k, k>0, then xf(x)=0
Example:
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When the exponent changes:
For an=a0n, or f(t)=x0t
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if -1<<1, then nan=0 or tf(t)=0
Example:
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if >1, then nan DNE or tf(t) DNE
Example:
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Rational expressions:
For an=bpnp+bp-1np-1+...+b1n+b0cqnq+cq-1nq-1+...+c1n+c0,
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if p<q, then nan=0
Example:
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if p=q, then nan=bpcq
Example:
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if p>q and both p and q are positive or negative, then nan= (DNE)
Example:
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if p>q and only one of p and q are positive, then nan=- (DNE)
Example:
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Sandwich Principle
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General case:
If nan=ncn=L and anbncn, then nbn=L
Example:
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Special case, Alternating sequences with (-1)n:
If nan=0, then nan=0, otherwise the limit DNE
Example:
Timothy John Beaulieu onto Limits
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