Explanation:
Given
f(x) = 4x³ + 3x² - 2x - 1
Divide it by the following:
(a) 2x + 1
4x³ + 3x² - 2x - 1 =
(4x³ + 2x²) + (x² + 1/2x) - (5/2x + 5/4) + 1/4 =
2x²(2x+1) + 1/2x(2x + 1) - 5/4(2x + 1) + 1/4 =
(2x + 1)(2x² + 1/2x - 5/4) + 1/4
Quotient = 2x² + 1/2x - 5/4
Remainder = 1/4
(b) 2x - 3
4x³ + 3x² - 2x - 1 =
(4x³ - 6x²) + (9x² - 13.5x) + (11.5x - 17.25) + 16.25 =
(2x -3)(2x² + 4.5x + 5.75) + 16.25
Quotient = 2x² + 4.5x + 5.75
Remainder = 16.25
(c) 4x - 1
4x³ + 3x² - 2x - 1 =
(4x³ - x²) + (4x² - x) - (2x - 1/2) - 3/2 =
(4x - 1)(x² + x - 1/2) - 3/2
Quotient = x² + x - 1/2
Remainder = - 3/2
(d) x + 2
4x³ + 3x² - 2x - 1 =
(4x³ + 8x²) - (5x² + 10x) + (8x + 16) - 17 =
(x + 2)(4x² - 5x + 8) - 17
Quotient = 4x² - 5x + 8
Remainder = - 17