Geometrymedium · Past Paper
The parametric equations of the circle x^2 + y^2 = r^2 are:
Ax = r cos theta, y = r sin theta
Bx = r sin theta, y = r cos theta
Cx = r sec theta, y = r tan theta
Dx = a cos theta, y = b sin theta
✓ Correct Answer: A — x = r cos theta, y = r sin theta
Substituting x = r cos theta and y = r sin theta into x^2 + y^2 gives r^2(cos^2 + sin^2) = r^2.
Share this question
More from Geometry
- If a chord AB of a circle subtends 60 degrees at the center, then the triangle OAB is:
- Calculate the area of a triangle with sides a=7, b=8, c=9.
- The length of the arc of a semicircle with radius 'r' is:
- What is the slope (gradient) of the line passing through (1, 2) and (3, 8)?
- If the angle between two radii of a circle is 130 degrees, the angle between the tangents at the ends of the radii is: