So I have this question:

> 
> Let $Q = (4, 8)$, $R = (6, 8)$ and $P = (a, b)$. Let $\lambda\in\mathbb R$ with $0 < \lambda < 1$.
> 
> 
> Consider $C =\{P: |QP| = \lambda|RP|\}$ 
> 
> 
> Give an equation to $C$ and prove its a circle.
> 
> 
> 

I'm trying to figure out how to interpret the $\lambda$ symbol to come up with the an expression for $C$, which I have to prove is a circle.

I did work out the distances $PQ$ and $QR$, the $\lambda$ symbol is just puzzling me.

I tried to fix $\lambda$ and divide the two distance equations, but it leads me nowhere.

Can anyone give me some directions?