Qeexid
(-iyo ..., m.dh) (xis.)Aragtida loo tibaaxo isle'egta f(x) = (x a)gx+f(a) taas oo micnaheedu yahay haddiitibxaale f(x) ee doorsoome x, loo qaybiyo (x a), oo a ay tahay madoorsoome; tibixdaharaaga waxa ay le'eg tahay qiimahatibxaalaha marka x = a. Tibxaalaha sare f(1) =2+3-1-4= 0, sidaa daraadeed (x-1) waa isir.