Materi persamaan eksponensial berbentuk.Ini bagaimana caranya?
Matematika
Joviabed
Pertanyaan
Materi persamaan eksponensial berbentuk.Ini bagaimana caranya?
1 Jawaban
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1. Jawaban DB45
Persamaan Ekponen
bentuk h(x)^f(x) = h(x)^g(x)
1) (x - 7)ˣ² ⁻² = (x - 7)ˣ
h(x) = x-7
f(x) = x² - 2
g(x) = x
a) f(x) = g(x)
x² - 2 = x --> x² - x - 2= 0
(x - 2)(x + 1) = 0
x = 2 atau x = - 1
b) h(x) = 1
x - 7 = 1 --> x = 6
c) h(x)= 0 , jika f(x) ,g(x) > 0
x - 7 = 0
x = 7
f(7) = 7² - 2 = 47 --> f(7) > 0
g(7) = 7 --> g(7) > 0
d) h(x) = - 1 , jika f(x), g(x) keduanya ganjil atau keduanya genap
x - 7 = -1
x = - 6
f(-6) = (-6)² - 2 = 34 --> f(-6) genap
g(-6) = -6 --> g(-6) genap
HP x = (-6, - 1 , 2 , 7, 8 )
2) (2x-5)ˣ²⁺¹ = (2x-5)ˣ⁺⁷
h(x) = 2x -5
f(x)= x² + 1
g(x)= x + 7
a) f(x) = g(x)
x² + 1 = x + 7
x² - x - 6 = 0
(x - 3)(x +2)= 0
x = 3 atau x = - 2
b) h(x)= 1
2x-5 = 1
x = 3
c) h(x) =0
2x -5 = 0
x = 5/2
f(5/2) = (5/2)² + 1 = 7 1/4 --> f(5/2) > 0
g(5/2) = 5/2 + 7 = 9 1/2 --> g(5/2) > 0
d) h(x) = -1
2x - 5 = - 1
x = 2
f(2) = 2² + 1 = 5 --> f(2) gnjil
g(2) = 2 +7 = 9 --> g(2) ganjil
HP x = (-2, 2 , 5/2 , 3)