Question

The equation $r^2=cos^2(\theta-\frac{\pi}{3})=2$ represents

• A. a parabola
• B. a hyperbola
• C. a circle
• D. a pair of straight line

Answer 1

Answer: (D)

a pair of straight line

Answer 2

$r\,cos\theta.\frac{1}{2}+r\,sin\theta.\frac{\sqrt3}{2}=2$

$r\,cos\theta+\sqrt3 r\,sin\theta=4$

$\Rightarrow \frac{r\,cos\theta}{4}+\frac{r\,sin\theta}{\frac{4}{\sqrt3}}=1$

Hence, This is a straight line
So, the correct option is (D) : a pair of straight line.