Question

write the range of 4, 5 and 6

Answer 1

Answer:

a)  [0 inf)

b)  [0 inf)

c)  [-1/2 1/2]

Step-by-step explanation:

c) Let y = x / (x²+1) ,

=> x² y + y = x ,

=> x²y - x + y = 0 ,

Discriminant  b²-4ac = (-1)² - 4 • y • y = 1 - 4y²

Now, Discriminant = 1 - 4y² ≥ 0 ,

(1)² - (2y)² ≥ 0 ,

( 1 + 2y )•( 1 - 2y ) ≥ 0 ,

( 2y + 1 )•( 2y - 1 ) ≤ 0 ,

( 2y + 1 ) ≥ 0 and ( 2y - 1 ) ≤ 0 ,

y ≥ -½ and y ≤ ½ ,

½ ≥ y ≥ -½ .