f(x) = 4x+5 g(x)= 6-x tentukan a) f-¹(x) b)g-¹(x) c)fog-¹(x)

a) f^-1(x)
y = f(x) = 4x+5
4x = y-5
x = (y-5)/4
f^-1(x) = (x-5)/4 = 1/4 x - 5/4
b) g^-1(x)
y = g(x) = 6-x
x = 6-y
g^-1(x) = 6-x
Yang c itu (fog)^-1(x) atau (fog^-1)(x)
kalau
(fog)^-1(x) = (g^-1 o f^-1)(x)
= g^-1((x-5)/4)
= 6-(x-5)/4 = (24-x+5)/4 = (29-x)/4
kalau
(fog^-1)(x) = f(g^-1(x))
= f(6-x) = 4(6-x) + 5 = 29-4x