f = Log[Erf[x/7]] - Cos[x^2 - 1] + 1; rts = Reduce[f == 0 && 1 < x < 6, x]
Plot[f, {x, 1, 6}, Epilog -> {Red, PointSize[0.025], Point[{x, f}] /. {ToRules[rts]}}]