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Diketahui polinomial   dan . Jika   adalah . . ..

Pertanyaan

Diketahui polinomial begin mathsize 14px style p left parenthesis x right parenthesis equals x to the power of 4 minus 2 x cubed plus 4 x squared minus 8 end style  dan begin mathsize 14px style q left parenthesis x right parenthesis equals 2 x to the power of 4 minus x cubed minus 5 x squared plus 3 x plus 12 end style. Jika begin mathsize 14px style r left parenthesis x right parenthesis equals p left parenthesis x right parenthesis minus q left parenthesis x right parenthesis comma space text nilai end text space r left parenthesis 2 right parenthesis end style  adalah . . ..

  1. begin mathsize 14px style 30 end style 

  2. begin mathsize 14px style 14 end style 

  3. begin mathsize 14px style negative 12 end style 

  4. begin mathsize 14px style negative 14 end style 

  5. begin mathsize 14px style negative 30 end style 

Pembahasan Video:

Pembahasan Soal:

Diketahui: begin mathsize 14px style p open parentheses x close parentheses equals x to the power of 4 minus 2 x cubed plus 4 x squared minus 8 end style dan begin mathsize 14px style q open parentheses x close parentheses equals 2 x to the power of 4 minus x cubed minus 5 x squared plus 3 x plus 12 end style 

Maka,

begin mathsize 14px style r open parentheses x close parentheses equals p open parentheses x close parentheses minus q open parentheses x close parentheses r open parentheses x close parentheses equals open parentheses x to the power of 4 minus 2 x cubed plus 4 x squared minus 8 close parentheses minus open parentheses 2 x to the power of 4 minus x cubed minus 5 x squared plus 3 x plus 12 close parentheses r open parentheses x close parentheses equals x to the power of 4 minus 2 x cubed plus 4 x squared minus 8 minus 2 x to the power of 4 plus x cubed plus 5 x squared minus 3 x minus 12 r open parentheses x close parentheses equals negative x to the power of 4 minus x cubed plus 9 x squared minus 3 x minus 20 end style  

Sehingga,

begin mathsize 14px style r left parenthesis x right parenthesis equals negative x to the power of 4 minus x cubed plus 9 x squared minus 3 x minus 20 r left parenthesis 2 right parenthesis equals negative left parenthesis 2 right parenthesis to the power of 4 minus left parenthesis 2 right parenthesis cubed plus 9 left parenthesis 2 right parenthesis squared minus 3 left parenthesis 2 right parenthesis minus 20 r left parenthesis 2 right parenthesis equals negative 16 minus 8 plus 36 minus 6 minus 20 r left parenthesis 2 right parenthesis equals negative 14 end style 

Jadi, jawaban yang benar adalah D.

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 12 April 2021

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