 Given the quadratic formula: $x = \frac{-b \pm \sqrt{b^2 -4ac}}{2a}$ Formatted in an R Markdown document as follows: $x = \frac{-b \pm \sqrt{b^2 -4ac}}{2a}$ We can substitute the following values: $a = `r# x(v$formula$quadratic$a)`, b = `r# x(v$formula$quadratic$b)`, c = `r# x(v$formula$quadratic$c)`$ `r# -x(v$formula$quadratic$b) + sqrt( v$formula$quadratic$b^2 - 4 * v$formula$quadratic$a * v$formula$quadratic$c )` To arrive at two solutions: $x = \frac{-b + \sqrt{b^2 -4ac}}{2a} = `r# (-x(v$formula$quadratic$b) + sqrt( x(v$formula$quadratic$b)^2 - 4 * x(v$formula$quadratic$a) * x(v$formula$quadratic$c) )) / (2 * x(v$formula$quadratic$a))`$ $x = \frac{-b - \sqrt{b^2 -4ac}}{2a} = `r# (-x(v$formula$quadratic$b) - sqrt( x(v$formula$quadratic$b)^2 - 4 * x(v$formula$quadratic$a) * x(v$formula$quadratic$c) )) / (2 * x(v$formula$quadratic$a))`$ Changing the variable values is reflected in the output immediately.