Jika x^1/2 + x^-1/2 = 2 Nilai x^2 + x^-2 adalah
Matematika
richards23
Pertanyaan
Jika x^1/2 + x^-1/2 = 2
Nilai x^2 + x^-2 adalah
Nilai x^2 + x^-2 adalah
1 Jawaban
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1. Jawaban arsetpopeye
x^1/2 + x^-1/2 = 2
(x^1/2 + x^-1/2)^2 = 2^2
(x^1/2)^2 + 2 . x^1/2 . x^-1/2 + (x^-1/2)^2 = 4
x + 2 + x^-1 = 4
x + x^-1 = 2
(x + x^-1)^2 = 2^2
x^2 + 2 . x . x^-1 + x^-2 = 4
x^2 + 2 + x^-2 = 4
x^2 + x^-2 = 2
Ingat : (a + b)^2 = a^2 + 2ab + b^2