Q19 of 57 Page 31

Prove that the following numbers are irrational numbers:


us consider that 2 + √2 is a rational number.

Let 2 + √2 = a/b for b ≠ 0 ……………… (i)


Where a and b are co-prime integer numbers.


From (i) we can write as follows:


a/b – 2 = √2



Now from the LHS we know that a and b are integral numbers and therefore the fraction will also be rational number which implies that √2 has to be a rational number. But we know that √2 is an irrational number.


So our assumption at the beginning of the problem is proved false.


So 2 + √2 is an irrational number.


More from this chapter

All 57 →