Which of the following points lies on the circle whose center is at the origin and whose radius is 10?

Question

alones · Answer

$$(0,2\sqrt{5})$$

aravindg · Answer

x^2+y^2=r^2 is general eqn of circle with centre (0,0) and radius r.

aravindg · Answer

Use it here.

alones · Answer

Okay the formula u man this one?
$$r=\sqrt{(x-0)^2+(y-0)^2}$$

aravindg · Answer

If the point satisfies the equation it is on the circle.

alones · Answer

*mean

aravindg · Answer

Yep same as yours.

alones · Answer

Oh lol mkay
Oh so this one is false 100=($2\sqrt{5}$)$^{2}$+0

aravindg · Answer

Yeah false

alones · Answer

Same thing with this one  100=( $\sqrt{10}$ )$^{2}+0$

alones · Answer

and the last choice for which i had is
WAIT @AravindG  IT SHOWS FALSEE ALSO
 100=($5\sqrt{5}$)$^{2}$+$\ (5\sqrt{5})^2$

alones · Answer

O.mg. so all of them are false.. how's that possible >.>

mayankdevnani · Answer

what are the options?

alones · Answer

Mkay
A. (√10, 0)
B. (0, 2√5)
C. (5√2, 5√2)

mayankdevnani · Answer

option C is correct

mayankdevnani · Answer

you made a typo in your solution

alones · Answer

Oh i jsut solved it.. and it doesn't mathces..

mayankdevnani · Answer

you took $$\large \bf 5\sqrt{5}~instead~of~5\sqrt{2}$$

alones · Answer

Oh shoot yea i took 5 

ooh my bad xP

mayankdevnani · Answer

its okay !

jim_thompson5910 · Answer

geogebra says that point C is on the curve. So you can use a visual tool like a graphing calculator to check