Prove or disprove that if a and b are rational numbers, then ab is rational
A Rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p, and a non-zero denominator q. Every integer is a rational number.
Answer: If a and b are rational numbers, then ab can be rational or irrational.
Prove/ disprove that if a and b are rational, then ab is rational
Let a=2 and b=4
ab = 24 = 16, which is a rational number.
Therefore, the statement is true.
Let a = 2 and b = 1/2
ab= 21/2 = √2 which is not a rational number