jangan dihapus lagi!! minta tolong nmr 3,5 sama 6

Nomor 3
Koordinat titik puncak f(x) = 2x² - 4x + 1
x = -b/2a
   = -(-4) / 2(2)
   = 4 / 4 = 1
y = 2x² - 4x + 1
   = 2(1)² - 4(1) + 1
   = -1
Koordinat titik puncak adalah (1,-1)

Nomor 5
[tex](f o g)(x) = 3 \sqrt{x+2} \\ \\ (f o g)(x) = \sqrt{9} . \sqrt{x+2} \\ \\ (f o g)(x) = \sqrt{9x+18} \\ \\ f(x)=\sqrt{x-1} \\ \\ f(g(x))= \sqrt{(9x+19)-1} \\ \\ g(x)=9x+19[/tex]

Nomor 6
f(x) = 2x + c
g(x) = 3x + 50

(g o f)(x) = (f o g)(x)
g(f(x)) = f(g(x))
3(2x + c) + 50 = 2(3x + 50) + c
6x + 3c + 50 = 6x + 100 + c
2c = 50
c = 25