# Find all x,y points on the graph if r*cos(p)<=2 and -pai<=p<=pai

#### queency3

##### New member
Find all x,y points on the graph if r*cos(p)<=2 and -pai<=p<=pai

I need to figure out why the answer to this question is (x-1)^2+y^2=1

Just to remind people here:
tan(p)=y/x
Cos(p)=y/r
r^2=x^2+y^2

Hope this helps..

Last edited by a moderator:

#### stapel

##### Super Moderator
Staff member
Find all x,y points on the graph if r*cos(p)<=2 and -pai<=p<=pai
What is "pai"? Is this meant to indicate [imath]\pi[/imath], or something else?

Does [imath]r\cdot \cos(p)[/imath] indicate a polar-coordinate expression?

I need to figure out why the answer to this question is (x-1)^2+y^2=1
Are you sure that this equality is the equivalent to the original INequality?

Just to remind people here:
tan(p)=y/x
cos(p)=y/r
r^2=x^2+y^2
What have you tried, working with the above information?

Eliz.

#### khansaheb

##### Full Member
(x-1)^2+y^2=1
Describe the graph you would get, if you plotted the equation above.