Apply division algorithm to find the quotient q(x) and remainder r(x) when f(x) = 10x⁴ + 17x³ − 62x² + 30x − 3 is divided by g(x) = 2x² + 7x + 1
Video Explanation
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Solution
Given:
f(x) = 10x⁴ + 17x³ − 62x² + 30x − 3
g(x) = 2x² + 7x + 1
Step 1: Apply the Division Algorithm
According to the division algorithm,
f(x) = g(x) · q(x) + r(x)
where the degree of r(x) is less than the degree of g(x).
Step 2: Divide f(x) by g(x)
10x⁴ + 17x³ − 62x² + 30x − 3 ÷ (2x² + 7x + 1)
First term:
10x⁴ ÷ 2x² = 5x²
Multiply:
5x²(2x² + 7x + 1) = 10x⁴ + 35x³ + 5x²
Subtract:
(10x⁴ + 17x³ − 62x²) − (10x⁴ + 35x³ + 5x²)
= −18x³ − 67x²
Bring down +30x:
−18x³ − 67x² + 30x
Next term:
−18x³ ÷ 2x² = −9x
Multiply:
−9x(2x² + 7x + 1) = −18x³ − 63x² − 9x
Subtract:
(−18x³ − 67x² + 30x) − (−18x³ − 63x² − 9x)
= −4x² + 39x
Bring down −3:
−4x² + 39x − 3
Next term:
−4x² ÷ 2x² = −2
Multiply:
−2(2x² + 7x + 1) = −4x² − 14x − 2
Subtract:
(−4x² + 39x − 3) − (−4x² − 14x − 2)
= 53x − 1
Step 3: Identify Quotient and Remainder
Quotient, q(x) = 5x² − 9x − 2
Remainder, r(x) = 53x − 1
Final Answer
Quotient: q(x) = 5x² − 9x − 2
Remainder: r(x) = 53x − 1
Conclusion
Thus, by applying the division algorithm, when f(x) = 10x⁴ + 17x³ − 62x² + 30x − 3 is divided by g(x) = 2x² + 7x + 1, the quotient is 5x² − 9x − 2 and the remainder is 53x − 1.