LIM (when x tends to infinity) x ^ 2 [1-cos (1 / x)]

LIM (when x tends to infinity) x ^ 2 [1-cos (1 / x)]

lim x->∞ x²[1 - cos(1/x)]
=Lim X - > ∞ [1 - cos (1 / x)] / (1 / X & # 178;) (the numerator and denominator tend to 0 at the same time, and the lobita rule can be used)
= lim x->∞ {0 - [-sin(1/x)] * [-x^(-2)]} / [-2x^(-3)]
=Lim X - > ∞ [sin (1 / x)] / (2 / x)
= lim x->∞ [cos(1/x) * (1/x)'] / (2/x)'
= lim x->∞ [cos(1/x)] / 2
= cos(0) / 2
= 1/2