Nomor 14 Beserta jalannya

Ingat :
f(x) = y
f^-1 y = x

f(x) = (x² - 4x + 7)/(x² - 2x + 1)
f^-1 (x² - 4x + 7)/(x² - 2x + 1) = x

f^-1 (1)
(x² - 4x + 7)/(x² - 2x + 1) = 1
x² - 4x + 7 = x² - 2x + 1
-4x + 2x = -7 + 1
-2x = -6
x = -6/-2
x = 3

Opsi : D