POLYNOMIALS AND
2. Find p(0),p(1) and p(2) for each of the following polynomials.
(1) p(x) = x2-x+1
(i) p(y) = 2 + y + 2y2 -y3
(ii). p(z)=z3
(iv) p(t) = (t-1)(t+1)
Answers
Answer:
1) p(0)=0×2-0+1=1
p(1)=1×2-1+1=2
p(2)=2×2-2+1=1
p(0)=2+0+2×0×2-0×3=2
p(1)=2+1+2×1×2-1×3=4
p(2)=2+2+2×2×2-2×3=6
Sol : a) If x = 0
p(x) = x
2
– x + 1
p(0) = (0)2
– (0) + 1
= 0 – 0 + 1
= 1
b) If x = 1
p(x) = x
2
– x + 1
p(1) = (1)2
– (1) + 1
= 1 – 1 + 1
= 1
c) If x = 2
p(x) = x
2
– x + 1
p(0) = (2)2
– (2) + 1
= 4 – 2 + 1
= 3
ii. p(y) = 2 + y + 2y2
– y
3
Sol : a) If y = 0
p(0) = 2 + 0 + 2(0)2
– (0)3
p(0) = 2 + 0 + 2(0) – (0)
= 2 + 0 + 0 – 0
= 2
b) If y = 1
p(1) = 2 + 1 + 2(1)
2
– (1)
3
p(1) = 2 + 1 + 2(1) – (1)
= 3 + 2 – 1
= 5 – 1
= 4
c) If y = 2
p(2) = 2 + 2 + 2(2)2
– (2)3
= 2 + 2 + 2(4) – (8)
2 + 2 +8 – 8
= 4
iii. p(z) = z3
Sol : a) If z = 0
p(0) = (0)3
p(0) = 03
= 0
b) If z = 1
p(1) = (1)3
p(1) = 13
= 1
c) If z = 2
p(2) = (2)3
p(2) = 23
= 8
iv. p(t) = (t – 1) (t + 1)
Sol : a) If t = 0
p(0) = (0 – 1) (0 + 1)
p(0) = (– 1) (1)
= – 1
b) If t = 1
p(1) = (1 – 1) (1 + 1)
p(1) = (0) (2)
= 0
c) If t = 2
p(2) = (2 – 1) (2 + 1)
p(0) = (1) (3)
= 3