Find the Zeros of p(y) = y² + (3√5/2)y − 5 and Verify the Relationship Between Zeros and Coefficients
Video Explanation
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Solution
Given polynomial:
p(y) = y² + (3√5/2)y − 5
Step 1: Find the Zeros of the Polynomial
y² + (3√5/2)y − 5 = 0
Multiply the whole equation by 2 to remove the fraction:
2y² + 3√5y − 10 = 0
Split the middle term:
2y² + 4√5y − √5y − 10 = 0
Grouping the terms:
2y(y + 2√5) − √5(y + 2√5) = 0
(2y − √5)(y + 2√5) = 0
∴ 2y − √5 = 0 or y + 2√5 = 0
∴ y = √5/2 or y = −2√5
Zeros of the polynomial are √5/2 and −2√5.
Step 2: Identify Coefficients
Comparing p(y) = y² + (3√5/2)y − 5 with ay² + by + c:
a = 1, b = 3√5/2, c = −5
Step 3: Verify the Relationship
Let α = √5/2 and β = −2√5
Sum of zeros:
α + β = √5/2 − 2√5 = −3√5/2
−b/a = −(3√5/2)/1 = −3√5/2
✔ Sum of zeros = −b/a
Product of zeros:
αβ = (√5/2)(−2√5) = −5
c/a = −5/1 = −5
✔ Product of zeros = c/a
Final Answer
Zeros of the polynomial are √5/2 and −2√5.
The relationship between zeros and coefficients is verified.
Conclusion
Thus, for the quadratic polynomial p(y) = y² + (3√5/2)y − 5, the sum and product of zeros satisfy the standard relationships with its coefficients.