The proof is by the method of reductio ad absurdum. We start by assuming that sqrt(2) is rational. That means that it can be expressed in the form p/q where p and q are co-prime integers. Thus sqrt(2) = p/q. This can be simplified to 2*q^2 = p^2 Now 2 divides the left hand side (LHS) so it must divide the right hand side (RHS). That is, 2 must divide p^2 and since 2 is a prime, 2 must divide p. That is p = 2*r for some integer r. Then substituting for p gives, 2*q^2 = (2*r)^2 = 4*r^2 Dividing both sides by 2 gives q^2 = 2*r^2. But now 2 divides the RHS so it must divide the LHS. That is, 2 must divide q^2 and since 2 is a prime, 2 must divide q. But then we have 2 dividing p as well as q which contradicts the requirement that p and q are co-prime. The contradiction implies that sqrt(2) cannot be rational.
This is impossible to prove, as the square root of 2 is irrational.
No; you can prove the square root of any positive number that's not a perfect square is irrational, using a similar method to showing the square root of 2 is irrational.
I linked a good resource that explains what you asked below.
The square root of 2 is an irrational number
If the positive square root (for example, square root of 2) is irrational, then the corresponding negative square root (for example, minus square root of 2) is also irrational.
This is impossible to prove, as the square root of 2 is irrational.
The square root of 2 is 1.141..... is an irrational number
It is known that the square root of an integer is either an integer or irrational. If we square root2 root3 we get 6. The square root of 6 is irrational. Therefore, root2 root3 is irrational.
No; you can prove the square root of any positive number that's not a perfect square is irrational, using a similar method to showing the square root of 2 is irrational.
I linked a good resource that explains what you asked below.
Yes. The square root of a positive integer can ONLY be either:* An integer (in this case, it isn't), OR * An irrational number. The proof is basically the same as the proof used in high school algebra, to prove that the square root of 2 is irrational.
It is not possible to prove something that is not true. The square of 2 is rational, not irrational.
The square root of 2 is an irrational number
Yes, the square root of 2 is an irrational number.
The square roots of 2 and 3 are irrational but not transcendent.
If the positive square root (for example, square root of 2) is irrational, then the corresponding negative square root (for example, minus square root of 2) is also irrational.
2 is a prime number and its square root is an irrational number that cannot be expressed as a fraction