Question

Sketch a circle with equation x^2+y^2=1. How many points on the circle have the property that cos s= 0?

Answer 1

@satellite73 @ParthKohli

Answer 2

@surjithayer

Answer 3

Did you know that the x-coordinate of this circle is cosine?

Answer 4

Shall I demonstrate this property?

Answer 5

no, this is so confusing :/

Answer 6

yes please

Answer 7

This is the graph of the circle \(x^2 + y^2 = 1\) (you know how to graph circles, right?)

Answer 8

I kind of forgot how to graph circles, I haven't done it since geometry, and this is algebra 2.

Answer 9

\[(x - h)^2 + (y - k)^2 = r^2\]The above is the general equation of any circle where \((h,k)\) is the centre and \(r\) is the radius.

Answer 10

Does that ring a bell?\[x^2 + y^2 = 1\] can be written as\[(x - 0)^2 + (y - 0)^2 = 1^2\]So the centre would be \((0,0)\) and the radius would be \(1\).

Answer 11

ahh Okay, thanks for refreshing my memory there.

Answer 12

The radius is the length of ALL the points falling on the circle from the centre.

Answer 13

The points that fall on the circle will be 1 unit away from the centre, as 1 is the radius. So all the points I have illustrated are on the circle, as they are 1 unit away from the centre (0,0).

Answer 14

Okay so radius =1

Answer 15

Now begins the fun part.