Question

Is log2 rational or irrational? justify your answer
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Answer 1

Assume that log 2 is rational, that is,

log2=p/q

where p, q are integers. Since log 1=0 and log10=1,0<log2<1  and p<q.

2=10^p/q

2^p=(2*5)^q

2^q-p=5^p

where q – p is an integer greater than 0.Now, it can be seen that the L.H.S. is even and the R.H.S. is odd. Hence there is contradiction and  log 2  is irrational.