1 of 2

Sol.

Exercise 2.3

On dividing x³ – 3x² + x + 2 by a polynomial g(x), the quotient

and remainder were x – 2 and – 2x + 4, respectively. Find g(x).

1.

Dividend

= Divisor

× Quotient

+ Remainder

x3 – 3x2 + x + 2

=

g(x)

×

(x – 2)

+

(–2x + 4)

g(x)

×

(x – 2)

=

x3 – 3x2 + x + 2

+ 2x – 4

g(x)

(x – 2)

=

x3 – 3x2 + x + 2

+ 2x – 4

g(x)

=

x3

– 3x2

+ 3x

– 2

(x – 2)

x3 – 3x2 + x + 2

=

g(x)

×

(x – 2)

– 2x + 4

+ 2

+ 2x

+ x

– 4

2 of 2

Sol.

Exercise 2.3

On dividing x³ – 3x² + x + 2 by a polynomial g(x), the quotient

and remainder were x – 2 and – 2x + 4, respectively. Find g(x).

1.

Dividend

= Divisor

× Quotient

+ Remainder

g(x)

=

x3

– 3x2

+ 3x

– 2

(x – 2)

x3

x

=

x3

2x2

x2

=

x2

x

=

x2

+

2x

x

=

x – 2

x3 – 3x² + 3x – 2

(–)

x3 – 2x2

(+)

+ 3x

– 2

x

x2 + 2x

(–)

– 2

(+)

x

x2

+

x2

x2

(x 2)

x

(x 2)

2

x

x

=

x

2

1

=

1

(x 2)

x – 2

(–)

(+)

0

+ 1

Quotient =

Remainder =

x2 x + 1

0

Dividend should

be in index form