Which of the following is a solution of x2 + 2x = -2?
(x + (-i + 1)), (x - (-i + 1)), (x - (-i - 1)), (x + (-i - 1))
Solution:
Given equation x2 + 2x = -2
⇒ x2 + 2x + 2 = 0
The given equation i.e. x2 + 2x + 2 is a quadratic equation of the form ax² + bx + c
Here a = 1, b = 2, c = 2
b² - 4ac = 2² - 4 ×1 × 2 = 4 - 8 = -4
The roots of the equation are as follows:
The roots of the quadratic equation ax² +bx + c are:
(1) (-b/2a) + (√b² - 4ac)/2a = [-2/(2 × 1)] + (√2² - 4 × 1 × 2)/(2 × 6) = (-1) + √-4/2 = -1 + i
(2) (-b/2a) - (√b² - 4ac)/2a = [-2/(2 × 1)] - (√2² - 4 × 1 × 2)/(2 × 6) = (-1/6) - √-4/2 = -1 - i
The two factors of the equation are: (x - (i - 1)) and (x - (-i - 1))
Hence from the given options,(x - (-i - 1)) is the solution.
Which of the following is a solution of x2 + 2x = -2?
Summary:
Factoring x2 + 2x +2 we get the factors (x - (i -1)) and (x - (-i -1)).Hence from the given options,(x - (-i - 1)) is the solution.
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