f(x) = 2x²+5x -3 tentukanlah invers nya

Bab Fungsi Komposisi
Matematika SMA Kelas X

f(x) = 2x² + 5x - 3
y = 2x² + 5x - 3
(2x² + 5x - 3)/2 = y/2
x² + 5x/2 - 3/2 = y/2
(x + 5/4)² - 31/4 = y/2
(x + 5/4)² = 31/4 + y/2
(x + 5/4)² = 31/4 + 2y/4
x + 5/4 = √((2y + 31)/4)
x = -5/4 + 1/2 √(2y + 31)
f⁻¹ (x) = -5/4 + (1/2) √(2x + 31)