If α and β are the zeros of the polynomial f(x) = x² − p(x + 1) − c such that (α + 1)(β + 1) = 0, find the value of c
Video Explanation
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Given
f(x) = x² − p(x + 1) − c
α and β are the zeros of the polynomial.
(α + 1)(β + 1) = 0
To Find
The value of c.
Solution
Step 1: Simplify the Polynomial
f(x) = x² − p(x + 1) − c
= x² − px − p − c
Step 2: Find α + β and αβ
Comparing with ax² + bx + d:
a = 1, b = −p, constant term = −(p + c)
Sum of zeros:
α + β = −b/a = p
Product of zeros:
αβ = −(p + c)
Step 3: Use the Given Condition
(α + 1)(β + 1) = αβ + α + β + 1
= [−(p + c)] + p + 1
= 1 − c
Given that:
(α + 1)(β + 1) = 0
∴ 1 − c = 0
∴ c = 1
Final Answer
The value of c is:
c = 1
Correct Option
(a) 1
Conclusion
Hence, if (α + 1)(β + 1) = 0 for the polynomial f(x) = x² − p(x + 1) − c, then the value of c is 1.