lim x mendekati 0 = x² per 1-√x²+1

lim x→0 x²/(1 - √(x² + 1)), Rasionalkan
= lim x→0 x²(1 + √(x² + 1))/(1 - (x² + 1))
= lim x→0 x²(1 + √(x² + 1))/-x²
= lim x→0 -(1 + √(x² + 1))
= -(1 + √(0 + 1))
= -2