anonymous 3 years ago CAN SOMEONE PLEASE HELP ME!! Convert x 2 + y 2 = 8 to a polar equation. r = 4 r² = 8 r² = 64

1. anonymous

is r the given?

2. anonymous

yes r is 8 its based off the formula x^2+y^2=8

3. anonymous

i think its the last one r^2=64 r=8

4. anonymous

x^2+y^2=8 ==> r^2=8

5. anonymous

how can r^2 be both 8 and 64?

6. anonymous

r^2=8

7. anonymous

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8. anonymous

r^3=64

9. anonymous

8^2=64

10. anonymous

no but when you are converting to a polar equation $r=\sqrt{x^2+y^2}$

11. anonymous

therefore $r^2=x^2+y^2$

12. anonymous

so you are replacing the $x^2+y^2$

13. anonymous

with $r^2$

14. anonymous

r^2=8

15. anonymous

?

16. anonymous

yes you are converting from a rectangular equation to a polar equation

17. anonymous

that's what is stated in the question to do

18. anonymous

thx

19. anonymous

but if you teacher wants r itself then r is $r=2\sqrt{2}$

20. anonymous

r cant be 4 because you have are taking the root of 8 not halving it

21. anonymous

ok