soal limit tolong bantu ya

limit bentuk 0/0

9. lim(x->3)  (9-x²) / {4 -√(x²+7)} ...kali akar sekawan
= (9-x²)(4 + √(x² +7)) / {16 -(x² +7)}
= (9-x²)(4 + √(x²+7)) / (9-x²)
= 4 + √(x²+7)
x = 3  ,limit = 4 + √(9+7)
limit = 4 +√16
limit = 4 + 4 = 8


18. lim (x->0) (1 - cos 2x)/(1 - cos 4x)
= lim(x->0) ( 1 -{ 1 - 2 sin² x) / (1 - { 1 - 2 sin² 2x)}
= lim(x->0)   ( 2 sin² x)/ (2 sin² 2x)
= 2(x)² / 2(2x)²
= 2 x² / 8x²
= 2/8
=1/4