Roboguru

Diketahui , tentukan

Pertanyaan

Diketahui begin mathsize 14px style f open parentheses 5 x minus 1 close parentheses equals 7 x squared plus 2 end style, tentukan begin mathsize 14px style f open parentheses x close parentheses equals horizontal ellipsis end style     

  1. begin mathsize 14px style fraction numerator 7 x squared minus 14 x plus 57 over denominator 25 end fraction end style 

  2. fraction numerator size 14px 7 size 14px x to the power of size 14px 2 size 14px plus size 14px 14 size 14px x size 14px minus size 14px 57 over denominator size 14px 25 end fraction 

  3. begin mathsize 14px style fraction numerator 7 x squared plus 14 x plus 57 over denominator negative 25 end fraction end style  

  4. begin mathsize 14px style fraction numerator negative 7 x squared plus 14 x plus 57 over denominator 25 end fraction end style  

  5. begin mathsize 14px style fraction numerator 7 x squared plus 14 x plus 57 over denominator 25 end fraction end style 

Pembahasan Soal:

Diketahui begin mathsize 14px style f open parentheses 5 x minus 1 close parentheses equals 7 x squared plus 2 end style, maka undefined adalah

* untuk mencari undefined maka kita perlu mencari invers dari begin mathsize 14px style 5 x minus 1 end style terlebih dahulu

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell g open parentheses x close parentheses end cell equals cell 5 x minus 1 end cell row y equals cell 5 x minus 1 end cell row cell 5 x end cell equals cell y plus 1 end cell row x equals cell fraction numerator y plus 1 over denominator 5 end fraction end cell row cell g to the power of negative 1 end exponent open parentheses y close parentheses end cell equals cell fraction numerator y plus 1 over denominator 5 end fraction end cell row cell g to the power of negative 1 end exponent open parentheses x close parentheses end cell equals cell fraction numerator x plus 1 over denominator 5 end fraction end cell row blank blank blank end table end style 

Jika begin mathsize 14px style f open parentheses 5 x minus 1 close parentheses equals 7 x squared plus 2 end style, maka undefined diperoleh dengan mensubstitusikan x dengan invers dari begin mathsize 14px style 5 x minus 1 end style yaitu begin mathsize 14px style fraction numerator x plus 1 over denominator 5 end fraction end style sebagai berikut:

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell f open parentheses 5 x minus 1 close parentheses end cell equals cell 7 x squared plus 2 end cell row cell f open parentheses x close parentheses end cell equals cell 7 open parentheses fraction numerator x plus 1 over denominator 5 end fraction close parentheses squared plus 2 end cell row blank equals cell 7 open parentheses fraction numerator x squared plus 2 x plus 1 over denominator 25 end fraction close parentheses plus 2 end cell row blank equals cell fraction numerator 7 x squared plus 14 x plus 7 over denominator 25 end fraction plus 2 end cell row blank equals cell fraction numerator 7 x squared plus 14 x plus 7 over denominator 25 end fraction plus 50 over 25 end cell row blank equals cell fraction numerator 7 x squared plus 14 x plus 57 over denominator 25 end fraction end cell row blank blank blank end table end style 

Jadi, jawaban yang tepat adalah E. 

 

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 15 Maret 2021

RUANGGURU HQ

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

Coba GRATIS Aplikasi Ruangguru

Produk Ruangguru

Produk Lainnya

Hubungi Kami

Ikuti Kami

©2021 Ruangguru. All Rights Reserved