Question

Solve. x2 + 4x + 1 = 0

Answer 1

Use quadratic formula:-\[\Huge{\color{blue}{-b \sqrt{b^2-4ac}\over2a}}\]

Answer 2

a=1, b=4, c=1
Put the values & get ur answer:)

Answer 3

???

Answer 4

-4\[-4\sqrt{b ^{2}}-4(1)(1)/2(1)\]

Answer 5

you need to general quadratic formula or you need to complete the square

the formula is \[x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]

where a = 1, b = 4 and c = 1

or by completing the square


let

\[x^2 + 4x + 1 = 0\]

find \[(\frac{4}{2})^2 = 4\]

you need the constant term to be 4

so add 3 to both sides

then

\[x^2 + 4x + 4 = 3\]

factorise

\[(x + 2)^2 = 3\]

take the square root of both sides

\[x + 2 = \pm \sqrt{3}\]

subtract 2 from both sides

\[x = -2 \pm \sqrt{3}\]