[Help: CAS Code] Comparing answers history view

[compsystems]

Example #1:

Steps

Step 1:
root:=√(2.) [enter] 1.41421356237

Step 2:
exact(root) == approx(root) [enter] true

Where:
left(exact(root)) ->1607521/1136689
right(approx(root)) -> 1.41421356237
then
1607521/1136689 == 1.41421356237 -> true

now

Step 3:
approx(root) [enter] 1.41421356237
Step 4:
exact(root) [enter] 1607521/1136689
Step 5:
Ans == [up][up][up] -> (0) false
1607521/1136689 == 1.41421356237 -> 0 // expr 2

Why two different answers?

1607521/1136689 == 1.41421356237 // expr1
1607521/1136689 == 1.41421356237 // expr2

expr1 same expr2 yes