Q2. p(x) = 2x⁴ - 3x³ + 2x² + 2x - 1 is divided by (x - 2) and q(x) = 3x³ - 2x² + x - 1 is divided by (x - 1). So, twice the sum of the remainders is:
(A) 21
(B) 35
(C) 54
(D) 40
Answers
Hint
- Remainder theorem
If we divide a polynomial by a linear polynomial, the remainder can be found by substituting the zero of the divisor.
Solution
is the remainder when is divided by . Similarly, is the remainder when is divided by .
So, the remainders are and respectively.
Twice the sum of the remainders is . It is option (D).
Given :-
p(x) = 2x⁴ - 3x³ + 2x² + 2x - 1 is divided by (x - 2) and q(x) = 3x³ - 2x² + x - 1 is divided by (x - 1)
To Find :-
Twice the sum of the remainders is:
Solution :-
x - 2 = 0
x = 2
p(2) = 2(2)⁴ - 3(2)³ + 2(2)² - 2(2) - 1
p(-2) = 2(16) - 3(8) + 2(4) - (4) - 1
p(-2) = 32 - 24 + 8 + 4 - 1
p(-2) = 32 - 24 + 8 + 4 - 1
p(-2) = 8 + 8 + 4 - 1
p(-2) = 20 - 1
p(-2) = 19
Now
x - 1 = 0
x = 0 + 1
x = 1
q(1) = 3(1)³ - 2(1)² + 1 - 1
q(1) = 3 × 1 - 2 × 1 + 1 - 1
q(1) = 3 - 2 + 1 - 1
q(1) = 4 - 3
q(1) = 1
Now
Twice the sum
2(19 + 1)
2(20)
40
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