ve an example of real numbers for which the following fails

ve an example of real numbers for which the following fails:

Solution

Given equation is a triangle inequality rule which cannot fail for any real values.
We can check for different real values for example,
a=3,b=2 => LHS=5, RHS=5. This obeys the inequality.
a=-3,b=2=> LHS=1, RHS=5. This obeys the inequality.
a=-3,b=-2=>LHS=5, RHS=5. This obeys the inequality.

Hence, this inequality cannot fail for any real values of a and b.