solve for the quadratic equation 3x^2 + 8x + 1 = 0
Answers
Answer:
Step by Step Solution
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Step by step solution :
STEP
1
:
Equation at the end of step 1
(3x2 + 8x) - 1 = 0
STEP
2
:
Trying to factor by splitting the middle term
2.1 Factoring 3x2+8x-1
The first term is, 3x2 its coefficient is 3 .
The middle term is, +8x its coefficient is 8 .
The last term, "the constant", is -1
Step-1 : Multiply the coefficient of the first term by the constant 3 • -1 = -3
Step-2 : Find two factors of -3 whose sum equals the coefficient of the middle term, which is 8 .
-3 + 1 = -2
-1 + 3 = 2
Observation : No two such factors can be found !!
The answer is x = (-4+√13)/ 3 and (-4-√13)/ 3
Given:
3x² + 8x + 1 = 0
To find:
Solve the quadratic equation 3x² + 8x + 1 = 0
Solution:
Compare given equation with ax² +bx +c = 0
⇒ a = 3, b = 8 and c = 1
As we know discriminant Δ = b² - 4ac
⇒ Δ = (8)² - 4(3)(1) = 64 - 12 = 52
As we know x = (-b ± √Δ)/2a
x = (-8 ± √52)/ 2(3) = -8 ± √4×13 / 6 = -8 ± 2√13 / 6
⇒ x = -8 + 2√13 / 6 and x = -8 - 2√13 / 6
⇒ x = 2(-4+√13) 6 x = 2(-4-√13)/ 6
⇒ x = (-4+√13)/ 3 x = (-4-√13)/ 3
Therefore, x = (-4+√13)/ 3 and (-4-√13)/ 3
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