## Yolo4mecuite 2 years ago 1. 0.817643 = rational or irrational 2. -√88 rational or irrational 3. -√169 rational or irrational 4. Estimate √58 to the nearest integer. Help! Thank you!

1. hba

Do you have an intuition about rational and irrational number ?

2. Yolo4mecuite

ummmm

3. Yolo4mecuite

What is that supposed to mean

4. hba

What is your mother toungue ?

5. Yolo4mecuite

That makes no sense

6. hba

Let me rephrase it for you, Do you know what a rational and irrational number is ?

7. AravindG

any number with terminating decimals is a rational number ,but those numbers having not-terminating(maybe repeating) decimals are irrational numbers.

8. Yolo4mecuite

Yes I do

9. hba

Is pi a rational or irrational number ?

10. Yolo4mecuite

irrational

11. hba

12. Yolo4mecuite

rationsl

13. AravindG

good :)

14. AravindG

i hope you understand it now :)

15. hba

So, 0.817643 is rational or irrational ?

16. Yolo4mecuite

Thanks

17. Yolo4mecuite

rational

18. hba

See, 0.5 =1/2 so rational.

19. Yolo4mecuite

right

20. Yolo4mecuite

Thanks anyways I got it

21. phi

rational means you can write it down as a decimal. irrational means the decimals keep going, never repeating, no rhyme or reason for what the next decimal will be pi is a good example. roots (in general) are irrational unless they are roots of perfect squares. example square root of 4 is 2 but sqrt(5) is irrational. btw, same idea for cube roots, etc...

22. Yolo4mecuite

Thankies!! :)

23. phi

The trick part in these questions is recognizing that a number is a perfect square. 169 is 13*13, so the square root of 169 is 13, and rational

24. phi

88 is 2*44 or 2*2*2*11 and so sqrt(88)= sqrt(2*2*2*11)= sqrt(2*2)*sqrt(2*11)= 2sqrt(22) and sqrt(22) is irrational, and 2 times an irrational is still irrational.

25. phi

4. Estimate √58 to the nearest integer. Are you allowed a calculator? Or did they give you a way to do this problem?

26. Yolo4mecuite

calculator

27. phi

find the square root, and round to the nearest whole number. to round, look at the digit in the tenths place (next to the decimal point) if 4 or less, drop the decimals and that is the answer if 5 or bigger, drop the decimals, but ADD 1 to the answer example: 100.3 to the nearest integer is 100 (3 is 4 or less, so drop the decimals) 210.50013 to the nearest integer is 210+1 (because 5 is 5 or bigger) you get 211

28. Yolo4mecuite

Alrighty thank you

29. phi

if you are not allowed a calculator, write down the squares near 58 7*7 is 49 58 is between them 8*8 is 64 58 is 9 away from 49 and 6 away from 64. so 58 is closer to 64 than it is to 49 that is a clue that sqrt(58) is closer to 8 than to 7