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Please help :( really need answer

Please help :( really need answer-example-1

1 Answer

5 votes

Answer:

Options (C) and (F)

Explanation:

Polynomial function is,

f(x) = x³ - x² - 5x - 3

Possible rational roots of the given function will be =
(\pm1, \pm3)/(\pm1)

By putting x = -1

f(-1) = (-1)³ - (-1)² -5(-1) - 3

= -1 - 1 + 5 - 3

= 0

Therefore, x = -1 will a root of the given function.

Now we apply synthetic division to get the other roots,

-1 | 1 -1 -5 -3

↓ -1 2 3

1 -2 -3 0

Therefore, factored form of the polynomial will be (x + 1)(x² - 2x - 3).

Now we will find the roots of (x² -2x - 3).

x² - 2x - 3 = x² - 3x + x - 3

= x(x - 3) + 1(x - 3)

= (x + 1)(x - 3)

For roots of the function, f(x) = 0

(x + 1)(x - 3) = 0

x = -1, 3

Therefore, roots of the function are x = -1, 3

Options (C) and (F) are the answers.

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