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Question
Find the roots of the following equation, if they exist, by applying the quadratic formula:
`2x^2 + 5sqrt(3)x + 6 = 0`
Sum
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Solution
Given: `2x^2 + 5sqrt(3)x + 6 = 0`
Step-wise calculation:
1. Compare with ax2 + bx + c = 0:
a = 2, b = `5sqrt(3)`, c = 6
2. Quadratic formula:
`x = (-b ± sqrt(b^2 - 4ac))/(2a)`
3. Discriminant:
D = b2 – 4ac
= `(5sqrt(3))^2 - 4 xx 2 xx 6`
= 75 – 48
= 27
4. `sqrt(D) = sqrt(27)`
= `3sqrt(3)`
5. `x = (-5sqrt(3) ± 3sqrt(3))/(2 xx 2)`
= `(-5sqrt(3) ± 3sqrt(3))/4`
`x_1 = (-5sqrt(3) + 3sqrt(3))/4`
= `(-2sqrt(3))/4`
= `(-sqrt(3))/2`
`x_2 = (-5sqrt(3) - 3sqrt(3))/4`
= `(-8sqrt(3))/4`
= `-2sqrt(3)`
The equation has two distinct real roots: `x = (-sqrt(3))/2` and `x = -2sqrt(3)`.
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