show that there's no rational number whose square is 8

Question

mathslover · Answer

Hello muteti, please post this question in Mathematics group. This is considered as Off-topic question as you have posted a Maths question in OpenStudy Feedback Group.

Also, a hint to your problem is , by considering that there is such a rational number whose square is 8 (Which is also known as contradiction method). 

If you still have any problem related to that, tag me there in the Maths group in your post.

Good Luck.

unklerhaukus · Answer

or you could find the square roots of 8, and prove it is not a rational number