Solve for x
by completing the square.
POLY_TEXT = 0
x = \quad
\quad \text{or} \quad x = \quad
x = \quad
X1
Begin by moving the constant term to the right side of the equation.
x^2 + Bx = C * -1
We complete the square by taking half of the coefficient of our x
term, squaring it, and adding it to both sides of the equation. Since the coefficient of our x
term is B
, half of it would be B / 2
, and squaring it gives us \color{blue}{pow( B / 2, 2 )}
.
x^2 + Bx \color{blue}{ + pow( B / 2, 2 )} = C * -1 \color{blue}{ + pow( B / 2, 2 )}
We can now rewrite the left side of the equation as a squared term.
( x + B / 2 )^2 = C * -1 + pow( B / 2, 2 )
The left side of the equation is already a perfect square trinomial. The coefficient of our x
term is B
, half of it is B / 2
, and squaring it gives us \color{blue}{pow( B / 2, 2 )}
, our constant term.
Thus, we can rewrite the left side of the equation as a squared term.
( x + B / 2 )^2 = C * -1 + pow( B / 2, 2 )
Take the square root of both sides.
x + B / 2 = \pmsqrt( C * -1 + pow( B / 2, 2 ) )
Isolate x
to find the solution(s).
x = -B / 2\pmsqrt( C * -1 + pow( B / 2, 2 ) )
x = -B / 2 + sqrt( C * -1 + pow( B / 2, 2 ) ) \text{ or } x = -B / 2 - sqrt( C * -1 + pow( B / 2, 2 ) )
x = -B / 2 + sqrt( C * -1 + pow( B / 2, 2 ) ) \text{ or } x = -B / 2 - sqrt( C * -1 + pow( B / 2, 2 ) )