Untitled 5 2

$$P(\frac{\pi }{3},2\cos \frac{\pi }{3})=(\frac{\pi }{3},1)$$ $$Q(\pi ,2\cos \pi )=(\pi ,-2)$$ $$PQ=\sqrt{{\left(\pi -\frac{\pi }{3}\right)}^2+(-2-1{)}^2}$$ $$=\sqrt{{\left(\frac{2\pi }{3}\right)}^2+9}$$ $$=\sqrt{\frac{4{\pi }^2}{9}+9}=3.7(1d.p.)$$