Sisa pembagian dari f(x) = 2x^5 - 6x^4 + x^³- 5x+15 jika dibagi (x-1) (x+1) (x-3) adalah Suku banyak f(x) = 8x³ + 42x² + ax – 5 habis dibagi 4x – 1. Nilai a da

jawab

1) pake horner
......2.....-6....1...0...-5....15
1............2...-4..-3...-3....-8
......2.....-4...-3..-3...-8....(7)
-1..........-2....6..-3....6
......2.....-6....3..-6...(-2)
3............6....0...9
......2......0....3...(3)

sisa = 3x²- 2x  + 6

2) f(x) = 8x³ +42x² + ax - 5
4x - 1= 0
x = 1/4
f(1/4) =0
8(1/64) + 42(1/16) + a(1/4) - 5 = 0
1/8 + 21/8 + a/4 - 5= 0 ...kalikan 8
1 + 21 + 2a - 40 =0
2a = 18
a = 9

hasil bagi  8x³ +42x²  + 9x - 5 ; (4x - 1)
= 2x² + 11x + 5