jika ²log(x²+1)=²log5 maka x

Kelas 10 Matematika
Bab Logaritma

²log (x² + 1) = ²log 5
x² + 1 = 5
x² + 1 - 5 = 0
x² - 4 = 0
(x + 2) (x - 2) = 0
x + 2 = 0
x = -2

x - 2 = 0
x = 2

Karena x² + 1 adalah imajiner, maka

Masukkan (-2)
x² + 1 
= (-2)² + 1
= 4 + 1
= 5

Masukkan (2)
x² + 1
= 2² + 1
= 4 + 1
= 5

Maka, 
x = -2 atau x = 2