Find the Zeros of q(y) = 7y² − (11/3)y − 2/3 and Verify the Relationship Between Zeros and Coefficients
Video Explanation
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Solution
Given polynomial:
q(y) = 7y² − (11/3)y − 2/3
Step 1: Find the Zeros of the Polynomial
7y² − (11/3)y − 2/3 = 0
Multiply the whole equation by 3 to remove fractions:
21y² − 11y − 2 = 0
Split the middle term:
21y² − 14y + 3y − 2 = 0
Grouping the terms:
7y(3y − 2) + 1(3y − 2) = 0
(7y + 1)(3y − 2) = 0
∴ 7y + 1 = 0 or 3y − 2 = 0
∴ y = −1/7 or y = 2/3
Zeros of the polynomial are −1/7 and 2/3.
Step 2: Identify Coefficients
Comparing q(y) = 7y² − (11/3)y − 2/3 with ay² + by + c:
a = 7, b = −11/3, c = −2/3
Step 3: Verify the Relationship
Let α = −1/7 and β = 2/3
Sum of zeros:
α + β = −1/7 + 2/3
= (−3 + 14)/21 = 11/21
−b/a = −[−11/3] / 7 = 11/21
✔ Sum of zeros = −b/a
Product of zeros:
αβ = (−1/7)(2/3) = −2/21
c/a = (−2/3) / 7 = −2/21
✔ Product of zeros = c/a
Final Answer
Zeros of the polynomial are −1/7 and 2/3.
The relationship between zeros and coefficients is verified.
Conclusion
Thus, for the quadratic polynomial q(y) = 7y² − (11/3)y − 2/3, the sum and product of zeros satisfy the standard relationships with its coefficients.