To find the value of 6β, we first evaluate the given limit:
β=limx→0xsin2xex3−(1−x3)31+((1−x2)21−1)sinx
We use the Taylor series expansions near x=0 for each component of the expression up to the x3 term:
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Expansion of ex3:
ex3=1+x3+O(x6)
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Expansion of (1−x3)31:
(1−x3)31=1−31x3+O(x6)
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Expansion of ((1−x2)21−1)sinx:
(1−x2)21=1−21x2+O(x4)
(1−x2)21−1=−21x2+O(x4)
Since sinx=x−6x3+O(x5), we have:
((1−x2)21−1)sinx=(−21x2+O(x4))(x+O(x3))=−21x3+O(x5)
Now, substitute these expansions into the numerator:
Numerator=(1+x3)−(1−31x3)−21x3+O(x5)
Numerator=(1−1)+(1+31−21)x3+O(x5)
Numerator=(66+2−3)x3+O(x5)=65x3+O(x5)
For the denominator, as x→0:
xsin2x=x(x+O(x3))2=x3+O(x5)
Substituting the numerator and denominator back into the limit:
β=limx→0x3+O(x5)65x3+O(x5)=limx→01+O(x2)65+O(x2)=65
Thus, the value of 6β is:
6β=6×65=5