Materi : Fungsi dan Relasi

Bagian A

f(x) = ( x + 4 )/( 2x - 5 )

Domain

2x - 5 ≠ 0

2x ≠ 5

x ≠ 5/2 { x | x ≠ 5/2, x ∈ R }

Invers

y = ( x + 4 )/( 2x - 5 )

x + 4 = y( 2x - 5 )

x + 4 = 2xy - 5

4 + 5 = 2xy - x

x( 2y - 1 ) = 9

x = 9/( 2y - 1 )

f-¹ = 9/( 2x - 1 )

Bagian B

f(x) = - 3x + 1

Domain

Pemisalan x = { 1, 2, 3 }

Maka Range = { -2, -5, -8 }

Invers

y = - 3x + 1

3x = y - 1

x = ( y - 1 )/3

f-¹(x) = ( x - 1 )/3

Bagian C

f(x) = x³

Domain

Pemisalan x = { 1, 2, 3 }

Maka Range = { 1, 8, 27 }

Invers

y = x³

x = ³√y

f-¹(x) = ³√x

Bagian D

f(x) = √[ x - 3 ]

Domain

Pemisalan x = { 7, 12, 19 }

Maka Range = { 2, 3, 4 }

Invers

y = √[ x - 3 ]

y² = x - 3

x = y² + 3

f-¹(x) = x² + 3

Semoga bisa membantu