Tolong dijawab ya pakai cara, nomer 21 & 22, makasih banyakk

Lim (1 - sin^2 x) / (sin 1/2 x - cos 1/2 x)^2
= (1 - sin^2 π) / (sin 1/2 π - cos 1/2 π)^2
= (1 - 0^2) / (1 - 0)^2
= 1/1
= 1

Lim (sin 2x)/(3 - √(2x + 9)) . (3 + √(2x + 9))/(3 + √(2x + 9))
= Lim (sin 2x)(3 + √(2x + 9)) / (9 - (2x + 9))
= Lim (sin 2x)/(-2x) . (3 + √(2x + 9))
= -2/2 . (3 + √(2.0 + 9))
= -1 . (3 + √9)
= -6