Consider the statement :
q : For any real numbers a and b, a2 = b2⇒ a = b
By giving a counter-example, prove that q is false.
Let us take the numbers a= +5 and b= -5.
a2 = (+5)2 = 25
b2 = (-5)2 = 25
∴ a2 = b2
But, +5 ≠ -5 ,thus a ≠ b.
∴ q is false.