Question: prove that 2 + root 3 upon 5 is an irrational number given that root 3 is an irrational number?
Answer: Let 2root 3 / 5 be a rational no. in the form a/b where, a and b are integers. ... But this contradicts tha fact that root3 is a rational no. So, our assumption is wrong and hence 2root3 / 5 is an irrational no.