Question

Выделите полный квадрат
-X^2+2x+1

Answer 1

x^2-2x-1=0
a = 1    b = -2  c = -1
D = b^2 - 4ac = (-2)^2 - 4 *1*(-1) = 4 + 4 = 8
VD = V8 = 2V2
x1 = 2 + 2V2  / 2 = 1+V2
x2 = 2 - 2V2 / 2 = 1 - V2