Question

Find the zeroes of the quadratic eqution, x2-2x-8​

Answer 1

Answer:

4 and -2

Explanation:

Given equation,

⇒ x² - 2x - 8

We need to find the zeros of the given quadratic equation.

Method (i) :-

Splitting the middle term,

⇒ x² - 4x + 2x - 8

⇒ x(x - 4) + 2(x - 4)

⇒ (x - 4)(x + 2)

⇒ x = 4

⇒ x = -2

∴ The zeros of the given polynomial is 4 and -2

Method (ii) :-

By quadratic formula,

→ [-b ± √(-b)² - 4ac]/2a

Where,

• a = 1 ; b = -2 and c = -8

Substituting the values,

→ [-(-2) ± √(-2)² - 4(1)(-8)]/2(1)

→ [2 ± √4 + 32]/2

→ [2 ± √36]/2

→ [2 ± 6]/2

→ 8/2 or, -4/2

→ 4 or, -2

Hence, the zeros are 4 and -2.

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