Question

Giving reason in each case, show that each of the following numbers is
irrational.
(a) 4+√5
(b) -3+√6
(c) 5√7
(d) −3√8
(e) 2/√5
(f) 4/√3

Answer 1

Step-by-step explanation:

Let as assume 4+√5 is rational

4+√5=a/b. (a,b are co primes)

√5=a-4b/b

RHS:a-4b/b is a rational

LHS:√5is irrational

so,our conctraduces that 4+√5is irrational

Answer 2

Answer:

now , we know that a , b and 4 all are integers . so we can write it as -

√5 = integers . all integers are rational no.' s also , so.

√5 = rational no. but it is proved that √5 is an irrational no. so our supposition is wrong .

hence , 4 + √5 is and irrational no. regards