What are the coordinates for the point p(45^circ) where p(theta)=(x,y) is the point where the terminal arm of an angle theta intersects the unit circl?

1 Answer
Aug 3, 2018

( 1/sqrt2, 1/sqrt 2 ). See graphical depiction.

Explanation:

The polar equation of this unit circle is r = 1.

A point of the radial line vec(OP), in the direction theta are

p ( theta ) = r ( cos theta, sin theta ).

If P is the point of intersection with r = 1,

p ( theta ) = ( cos theta, sin theta ).. So,

p ( pi/4 ) = ( cos (pi/4), sin (pi/4)) = ( 1/sqrt 2, 1/sqrt 2 ).

See graphical depiction.

graph{(x^2+y^2-1)(y-x)((x-1/sqrt2)^2+(y-1/sqrt2)^2-0.001)=0[0 2 0 1]}