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5 votes
5 votes
Find the roots


\sf x^2+3x+5=0

Use quadratic formula

Note:-

Plagarised/spam/short answers will be deleted on the spot.

Answer with all steps and proper explanation .

Hint:-

irrational roots will come ​

User Otravers
by
2.8k points

2 Answers

30 votes
30 votes

Answer:


⇒x = \frac{ - b \binom{ + }{ - } \sqrt{ {b}^(2) } - 4ac }{2a}

Once in standard form, identify a, b and c from the original equation and plug them into the quadratic formula.


⇒ {x}^(2) + 3x + 5 = 0 \\ ⇒a = 1 \\ ⇒b = 3 \\ ⇒c = 5 \\ ⇒x = \frac{ - 3 \binom{ + }{ - } \sqrt{ {3}^(2) } - 4.1.5}{2.1}

▪Evaluate the exponent

▪Multiply the numbers

▪Subtract the numbers

▪Multiply the numbers


⇒x = \frac{ - 3 \binom{ + }{ - } √( - 11) }{2}

▪The square root of a negative number is not a real number


⇒d = - 11

no solution

User Nick VanderPyle
by
2.9k points
21 votes
21 votes


\sf \: {x}^(2) + 3x + 5 = 0

Solve the quadratic equation (ax²+bx+c=0) using the quadratic formula:


\boxed{ \bf \: x = \frac{ - b± \sqrt{ {b}^(2) - 4ac } }{2a} }

  • a = 1
  • b = 3
  • c = 5


\tt \: x = \frac{ - 3± \sqrt{ {3}^(2) - 4 * 1 * 5 } }{2 * 1}

Any expression multiplied by 1 remains the same


\tt \: x = \frac{ - 3± \sqrt{ {3}^(2) - 4 * 5 } }{2}

Evaluate the power


\tt \: x = ( - 3± √(9 - 4 * 5) )/(2)

Multiply the numbers


\tt \: x = ( - 3± √(9 - 20) )/(2)

Calculate the difference


\tt \: x = ( - 3± √( - 11) )/(2)

Calculate the square root


\tt \: x = ( - 3± √(11)i )/(2)

Write the solutions, one with a + sign and one with a - sign


\tt \: x = ( - 3 + √(11) i)/(2) \\ \tt \: x = ( - 3 - √(11)i )/(2)

Separate the real and the imaginary parts


\tt \: x = - (3)/(2) + ( √(11) )/(2) i \\ \tt \: x = - (3)/(2) - ( √(11) )/(2) i

∴ The quadratic equation has two solutions


\rm x_(1) = - (3)/(2) + ( √(11) )/(2) i, x_(2) = - (3)/(2) - ( √(11) )/(2) i

User HirenParekh
by
2.7k points
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