False position method double false position became a root-finding algorithm used in iterative numerical approximation techniques. Many equations, including most of the more complicated ones, can be solved only by iterative numerical approximation. This consists of trial and error, in which various values of the unknown quantity are tried. That trial-and-error may be guided by calculating, at each step of the procedure, a new estimate for the solution. There are many ways to arrive at a calculated-estimate and "regula falsi" provides one of these. Given an equation, move all of its terms to one side so that it has the form, , where
Midfielder mark specific opposition attackers. Defensive midfielders may also move to the full-back or centre-back positions if those players move forward to join in an attack. Sergio Busquets described his attitude: "The coach knows that I am an obedient player who likes to help out and if I have to run to the wing to cover someone's position, great." A good defensive midfielder needs good positional awareness, anticipation of opponent's play, marking, tackling, interceptions, passing and great stamina and strength (for their tackling). A holding or deep-lying midfielder stays close to their team's defence, while other midfielders may move forward to