Find the range of y = (x2-2x-3) / (2x2 + 2x + 1) The range of y = (x2-2x-3) / (2x2 + 2x + 1) (2 after X means square)

Find the range of y = (x2-2x-3) / (2x2 + 2x + 1) The range of y = (x2-2x-3) / (2x2 + 2x + 1) (2 after X means square)

y=(x^2-2x-3)/2x^2+2x+1,x^2-2x-3=2yx^2+2yx+y
(2y-1)x^2+(2y+2)x+y+3=0
(2y+2)^2-4(2y-1)(y+3)>=0
-4=