If β = lim_(x → 0) (e^(x³) - (1 - x³)^(1/3) + ((1 - x²)^(1/2) - 1)sin x)/(x sin² x), then the value of 6β is ______.
β=limx→0xsin2xex3−(1−x3)1/3+((1−x2)1/2−1)sinx
At x→0: numerator→0, denominator→0⇒00 form
Find β, then 6β
Plan: expand numerator & denominator in powers of x, keep leading terms
sinx=x−6x3+⋯⇒sin2x≈x2
xsin2x≈x⋅x2=x3
ex3=1+x3+2x6+⋯
(1−x3)1/3=1−3x3−9x6+⋯
ex3−(1−x3)1/3=x3+3x3+⋯=34x3+⋯
(1−x2)1/2−1=−2x2+⋯,sinx≈x
((1−x2)1/2−1)sinx=−2x3+⋯
num=34x3−21x3+⋯
=(34−21)x3=65x3+⋯
β=limx→0x3+⋯65x3+⋯=65
6β=6⋅65=5
6β=5
β=65,6β=5