## iheartfood 2 years ago Which of the following could be points on the unit circle? (answer choices attached!) ***CHOOSE ALL THAT APPLY!!!!

1. iheartfood

answer choices A,B,C,D from top to bottom... im not really sure on this one... pls explain! thanks! :) ***choose ALL that apply :)

2. iheartfood

thanks for coming :) do y'all get this one?

3. mathstudent55

The equation of the unit circle is x^2 + y^2 = 1 Any point that makes the equation true is a point on the unit circle.

4. iheartfood

okay lemme try plugging em in... one sec!

5. iheartfood

i tried the first one and it didn't work...... i got 1.34... did i do that right?? so A is WRONG right? :)

6. iheartfood

and for the second choice, i got 1.4444444... so that's wrong also right?

7. iheartfood

but (1,1) =1 when i plug in so C is an answer right?! :)

8. mathstudent55

Try the second one again.

9. iheartfood

and for the last one, i got .28... so that's wrong right?? D is NOT an answer right?

10. mathstudent55

(1, 1) x^2 + y^2 = 1 1^2 + 1^2 = 1? 1 + 1 = 1 Not true, so (1, 1) is not a point on the unite circle.

11. iheartfood

oh okay i did it again... i got 1 lol so B is an answer yes?

12. mathstudent55

You are doing your math wrong.

13. mathstudent55

Two work and two don't work.

14. iheartfood

ohhh and i see for C... lol my bad!!! :P so A and C are out... and B is an answer?

15. iheartfood

and lemme try D again... and D is 1 as well.. my bad.. i entered them all weird in my calc so everything was wrong.. my bad!!! LOL sorry bout that... so B and D are the answers?

16. mathstudent55

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17. mathstudent55

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18. iheartfood

i see.. so my answers are B and D then right??

19. mathstudent55

C doesn't work. I showed you above.

20. mathstudent55

Yes.

21. iheartfood

awesome! Thanks :)

22. mathstudent55

(0.8)^2 + (-0.6)^2 = 1? 0.64 + 0.36 = 1? 1 = 1 It works. D is true

23. mathstudent55

wlcm