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
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