Question

Tolong bantu no 9 dan 10

Answer 1

Verified answer

9) f(x) = 1/3 x^3 - 4x + a naik jika f'(x) > 0
f'(x) = x^2 - 4 > 0
=> (x + 2)(x - 2) > 0
=> x = -2 atau x = 2
Garis bilangan
+++ (-2) --- (2) +++
x < -2 atau x > 2

10) u = AG = g - a = (0, 2, 2) - (2, 0, 0) = (-2, 2, 2)
v = AB = b - a = (2, 2, 0) - (2, 0, 0) = (0, 2, 0)
|v| = √(0^2 + 2^2 + 0^2) = √4 = 2
u.v = -2(0) + 2(2) + 2(0) = 4

Panjang proyeksi u pada v = (u.v)/|v| = 4/2 = 2