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Find the zeros of the function f(x) = - 1.9x squared- 4.3x + 1

1 Answer

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Answer:

x = sqrt(2609)/38 - 43/38 or x = -43/38 - sqrt(2609)/38

Explanation:

Solve for x:

-1.9 x^2 - 4.3 x + 1 = 0

-1.9 x^2 - 4.3 x + 1 = -(19 x^2)/10 - (43 x)/10 + 1:

-(19 x^2)/10 - (43 x)/10 + 1 = 0

Multiply both sides by -10/19:

x^2 + (43 x)/19 - 10/19 = 0

Add 10/19 to both sides:

x^2 + (43 x)/19 = 10/19

Add 1849/1444 to both sides:

x^2 + (43 x)/19 + 1849/1444 = 2609/1444

Write the left hand side as a square:

(x + 43/38)^2 = 2609/1444

Take the square root of both sides:

x + 43/38 = sqrt(2609)/38 or x + 43/38 = -sqrt(2609)/38

Subtract 43/38 from both sides:

x = sqrt(2609)/38 - 43/38 or x + 43/38 = -sqrt(2609)/38

Subtract 43/38 from both sides:

Answer: x = sqrt(2609)/38 - 43/38 or x = -43/38 - sqrt(2609)/38

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