Question 417010
 Square root is defined where the radical is positive 0r zero.
x^2-6x+8>=0; D=(-6)^2-4(1)(8)=36-32=4; x1/2=(6+-2)/2 {4,2} The domain is;
(-infinity,2]U[4,+infinity) or D={x real such that x<=2 and x>=4 }