In Regula-falsi method, the first approximation is given by
1
\({x_1} = \frac{{af\left( b \right) - bf\left( a \right)}}{{f\left( b \right) - f\left( a \right)}}\)
2
\({x_1} = \frac{{bf\left( b \right) - af\left( a \right)}}{{f\left( b \right) - f\left( a \right)}}\)
3
\({x_1} = \frac{{af\left( b \right) - bf\left( a \right)}}{{f\left( b \right) + f\left( a \right)}}\)
4
\({x_1} = \frac{{bf\left( b \right) - af\left( a \right)}}{{f\left( b \right) + f\left( a \right)}}\)