Review question

# When does this equation in $x, y$ and $\theta$ represent a circle? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R7378

## Question

Given $\theta$ in the range $0\leq \theta < \pi$, the equation $x^2+y^2+4x \cos\theta+8y \sin\theta+10=0$ represents a circle for
1. $0<\theta<\dfrac{\pi}{3}$;
2. $\dfrac{\pi}{4}<\theta<\dfrac{3\pi}{4}$;
3. $0<\theta<\dfrac{\pi}{2}$;
4. all values for $\theta$.