# Math Help - finding parametric representation of half circle

1. ## finding parametric representation of half circle mmn16 1a

i have a curve from(-2,0) to (2,0) half circle

how to find the formula for x
and y
?

i know that its some sort of trigonometric expression

2. Originally Posted by transgalactic
i have a curve from(-2,0) to (2,0) half circle

how to find the formula for x
and y
?

i know that its some sort of trigonometric expression
At the level you're studying at you're expected to know this.

x = 2 cos(t)
y = 2 sin(t)

The domain of t is left for you to find.

3. x=R*cos(t)
y=R*sin(t)

{IT BECAUSE x^2+y^2=R^2 describes a circle}