Question

решите неравенство (2-x)^2<5

Answer 1

$(2-x)^2 textless 5, \ 4-4x+x^2-5 textless 0, \ x^2-4x-1 textless 0, \ x^2-4x-1=0, \ D_{/4}=5, x_1=2-sqrt5, x_2=2+sqrt5, \ a=1 textgreater 0, \ xin(2-sqrt5;2+sqrt5).$