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3. Find a quadratic polynomial whose one zero is 5 + √3 and sum of the zeroes is 10.

1 Answer

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Answer:

f(x) = x² - 10x + 22

Explanation:

Let's assume the quadratic polynomial as:

f(x) = ax² + bx + c

Now we know that if one of the zeroes is 5 + √3, then the other zero must be 5 - √3 (because complex roots always come in conjugate pairs).

So the sum of the zeroes will be:

(5 + √3) + (5 - √3) = 10

10 = 2 * 5

The product of the zeroes will be:

(5 + √3) * (5 - √3) = 25 - 3 = 22

Now, using the sum and product of zeroes, we can write:

b/a = 10

c/a = 22

Solving for b and c, we get:

b = -10a

c = 22a

Substituting these values in f(x), we get:

f(x) = a(x - 5 - √3)(x - 5 + √3)

Expanding the right-hand side:

f(x) = a[(x - 5)² - (√3)²]

f(x) = a(x² - 10x + 22)

Comparing the coefficients of f(x) with ax² + bx + c, we get:

a = 1, b = -10, c = 22

Therefore, the quadratic polynomial is:

f(x) = x² - 10x + 22

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User Nicollette
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