Iklan

Iklan

Pertanyaan

Diketahui f − 1 ( x ) = 2 x − 3 x + 4 ​ . Jika g ( x ) = 3 x + 2 , tentukanlah ( f ∘ g ) − 1 ( x ) .

Diketahui . Jika , tentukanlah .

Iklan

Y. Fathoni

Master Teacher

Mahasiswa/Alumni Universitas Negeri Yogyakarta.

Jawaban terverifikasi

Jawaban

dipeoleh .

dipeoleh begin mathsize 14px style open parentheses f ring operator g close parentheses to the power of negative 1 end exponent open parentheses x close parentheses equals fraction numerator negative 3 x plus 10 over denominator 6 x minus 9 end fraction end style.

Iklan

Pembahasan

Gunakan sifat invers fungsi komposisi dan rumus praktis invers fungsi berikut: Diketahui: Akan ditentukan . Tentukan terlebih dahulu dengan menggunakan rumus praktis, diperoleh: Sehingga diperoleh dengan perhitungan berikut: Jadi, dipeoleh .

Gunakan sifat invers fungsi komposisi dan rumus praktis invers fungsi berikut:

begin mathsize 14px style open parentheses f ring operator g close parentheses to the power of negative 1 end exponent open parentheses x close parentheses equals open parentheses g to the power of negative 1 end exponent ring operator f to the power of negative 1 end exponent close parentheses open parentheses x close parentheses f open parentheses x close parentheses equals a x plus b rightwards double arrow f to the power of negative 1 end exponent open parentheses x close parentheses equals fraction numerator x minus b over denominator a end fraction end style  

Diketahui:
begin mathsize 14px style f to the power of negative 1 end exponent open parentheses x close parentheses equals fraction numerator x plus 4 over denominator 2 x minus 3 end fraction end style

begin mathsize 14px style g open parentheses x close parentheses equals 3 x plus 2 end style

Akan ditentukan begin mathsize 14px style open parentheses f ring operator g close parentheses to the power of negative 1 end exponent open parentheses x close parentheses end style.

Tentukan terlebih dahulu begin mathsize 14px style g to the power of negative 1 end exponent open parentheses x close parentheses end style dengan menggunakan rumus praktis, diperoleh:

begin mathsize 14px style g open parentheses x close parentheses equals 3 x plus 2 rightwards double arrow g to the power of negative 1 end exponent open parentheses x close parentheses equals fraction numerator x minus 2 over denominator 3 end fraction end style 

Sehingga diperoleh begin mathsize 14px style open parentheses f ring operator g close parentheses to the power of negative 1 end exponent open parentheses x close parentheses end style dengan perhitungan berikut:

begin mathsize 14px style table attributes columnalign right center left columnspacing 2px end attributes row cell open parentheses f ring operator g close parentheses to the power of negative 1 end exponent open parentheses x close parentheses end cell equals cell open parentheses g to the power of negative 1 end exponent ring operator f to the power of negative 1 end exponent close parentheses open parentheses x close parentheses end cell row blank equals cell g to the power of negative 1 end exponent open parentheses f to the power of negative 1 end exponent open parentheses x close parentheses close parentheses end cell row blank equals cell g to the power of negative 1 end exponent open parentheses fraction numerator x plus 4 over denominator 2 x minus 3 end fraction close parentheses end cell row blank equals cell fraction numerator open parentheses begin display style fraction numerator x plus 4 over denominator 2 x minus 3 end fraction end style close parentheses minus 2 over denominator 3 end fraction end cell row blank equals cell fraction numerator begin display style fraction numerator x plus 4 over denominator 2 x minus 3 end fraction end style minus begin display style fraction numerator 2 open parentheses 2 x minus 3 close parentheses over denominator 2 x minus 3 end fraction end style over denominator 3 end fraction end cell row blank equals cell fraction numerator begin display style fraction numerator x plus 4 minus 4 x plus 6 over denominator 2 x minus 3 end fraction end style over denominator 3 end fraction end cell row blank equals cell fraction numerator begin display style fraction numerator negative 3 x plus 10 over denominator 2 x minus 3 end fraction end style over denominator 3 end fraction end cell row blank equals cell fraction numerator negative 3 x plus 10 over denominator 2 x minus 3 end fraction cross times 1 third end cell row cell open parentheses f ring operator g close parentheses to the power of negative 1 end exponent open parentheses x close parentheses end cell equals cell fraction numerator negative 3 x plus 10 over denominator 6 x minus 9 end fraction end cell end table end style 

Jadi, dipeoleh begin mathsize 14px style open parentheses f ring operator g close parentheses to the power of negative 1 end exponent open parentheses x close parentheses equals fraction numerator negative 3 x plus 10 over denominator 6 x minus 9 end fraction end style.

Perdalam pemahamanmu bersama Master Teacher
di sesi Live Teaching, GRATIS!

22

Iklan

Iklan

Pertanyaan serupa

Diketahui fungsi f : R → R dan g : R → R dirumuskan oleh f ( x ) = x − 2 2 x + 1 ​ , x  = 2 dan g ( x ) = x + 3 . Jika h ( x ) = ( f ∘ g ) ( x ) . Tentukanlah invers h ( x ) .

19

3.8

Jawaban terverifikasi

RUANGGURU HQ

Jl. Dr. Saharjo No.161, Manggarai Selatan, Tebet, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta 12860

Coba GRATIS Aplikasi Roboguru

Coba GRATIS Aplikasi Ruangguru

Download di Google PlayDownload di AppstoreDownload di App Gallery

Produk Ruangguru

Hubungi Kami

Ruangguru WhatsApp

+62 815-7441-0000

Email info@ruangguru.com

[email protected]

Contact 02140008000

02140008000

Ikuti Kami

©2024 Ruangguru. All Rights Reserved PT. Ruang Raya Indonesia