x>=0 y=x^2-2x парабола ветви вверх нули 2 и 0
*****************************************************ответ: 11
Sin2x+cos2x+1=0
√2(√2/2sin2x+√2/2cos2x)=-1
√2(sin2xcosπ/4+cos2xsinπ/4)=-1
sin(2x+π/4)=-√2/2
2x+π/4=(-1)^n+1 *π/4+πn
2x=-π/4+(-1)^n+1*π/4+πn
x=-π/8+(-1)^n+1*π/8+πn/2