Re: [考古] 93政大財政
※ 引述《bitchdog (PEaCE)》之銘言:
: Find the values of a and b , if the limit
: √ ̄ ̄ ̄ ̄ ̄
: lim 1+x+x^2 -(1+ax)
: x→ 0  ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄= b
: X^2
: 打的爛
: 還請多多包含
by L'hopital Rule
lim {(1+2x)/[2√(1+x+x^2)]} -a
---------------------------
x→ 0 2x
lim 1+2x - 2a√(1+x+x^2)
= ---------------------
x→ 0 4x√(1+x+x^2)
極限存在
lim
(1+2x - 2a√(1+x+x^2)) = 0 => a= 1/2 代回上式
x->0
lim 1+2x - √(1+x+x^2)
--------------------
x→ 0 4x√(1+x+x^2)
lim 2 - {(1+2x)/[2√(1+x+x^2)]}
= ------------------------------------------ = 3/8 = b
x→ 0 4√(1+x+x^2) + {[2x(1+2x)]/√(1+x+x^2)}
a = 1/2 , b= 3/8
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※ 編輯: Fubini 來自: 140.112.128.88 (09/22 00:56)
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