i am trying to solve the following but i cant figure out the last line of the solution

\(\displaystyle 2x^2 \geq (x+1)^2\)

rearranging i get \(\displaystyle 2x^2 \geq x^2+2z+1\)

\(\displaystyle x^2-2x-1\geq 0\)

\(\displaystyle (x-1)^2 \geq 2\) This is the last step given in the solution i can understand how to get to this point but i dont know where\(\displaystyle \geq2\) comes from any help would be appreciated