mohon bantuan nya untuk menjawab nya mas mbak, soalnya bsk di Kumpulin... nuhun...
Matematika
ziddan31
Pertanyaan
mohon bantuan nya untuk menjawab nya mas mbak, soalnya bsk di Kumpulin...
nuhun...
nuhun...
1 Jawaban
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1. Jawaban Ashiela
1) f(x) = 4 / 2(3-x) = 2 / (3-x)
y = 2 / (3-x)
y(3-x) = 2
3y - xy = 2
3y - 2 = xy
x = (3y-2)/y
→ invers f(x) = (3x-2)/x
invers f(4) = (3.4-2)/4
= (12-2)/4 = 10/4 = 5/2
2) f(x) = 4x + 12
y = 4x + 12
y - 12 = 4x
x = ¼(y-12)
→ invers f(x) = ¼(x-12)
3) f(x) = 2x / (2x-2)
y = 2x / (2x-2)
y(2x-2) = 2x
2xy - 2y = 2x
2xy - 2x = 2y
x(2y-2) = 2y
x = 2y / (2y-2)
→ invers f(x) = 2x / (2x-2)
4) f(x) = 4x
g(x) = 6 - 10x
(g•f)(x) = 6 - 10(4x) = 6 - 40x
y = 6 - 40x
40x = 6 - y
x = (6-y)/40
→ invers (g•f)(x) = (6-x)/40
5) f^-1(x) = 6x + 3
g^-1(x) = x²
(f•g)^-1(x)
= (g^-1 • f^-1)(x)
= (6x + 3)² = 36x² + 36x + 9
6) g(x) = 6-10x
(g•f)(x) = 6-20x
6 - 10(f(x)) = 6 - 20x
6 - 6 + 20x = 10 (f(x))
20x = 10 (f(x))
f(x) = 20x/10 = 2x
7) f(x) = 4x²-6
f(f(x)) = f(4x²-6)
= 4(4x²-6)²-6
= 4(16x⁴-48x²+36)-6
= 64x⁴-192x²+144-6
= 64x⁴ - 192x² + 138
8) f(x) = 4x + 2x = 6x
g(x) = 2x²+2
h(x) = 4x
(h•g•f)(x)
= h(g(6x))
= h(2(6x)²+2)
= h(12x²+2)
= 4(12x²+2) = 48x²+8
9) f(x) = 4x
(f•g)(x) = -½x + 1
4 g(x) = -½x + 1
g(x) = ¼(-½x+1)
g(x) = -⅛x + ¼
10) f(x) = 8x
g(x) = 2 + 2x²
h(x) = 2x-4
(f•g•h)(x)
= f(g(2x-4))
= f(2 + (2+2x)²)
= 8(2 + (2+2x)²)
(f•g•h)(2)
= 8(2+ (2+2.2)²)
= 8 (2 + 6²)
= 8 (38) = 304