Question

The distance between the points $(a\cos {25}^o,0)$ and $(0,a\cos {65}^o)$ is ______.

• A. $a$
• B. $2a$
• C. $3a$
• D. $5a$

Answer 1

The correct option is A $a$

Distance between given two points $=\sqrt{(a\cos {25}^{\circ }-0{)}^2+(0-a\cos {65}^{\circ }{)}^2}=a\left(\sqrt{{\cos }^2{25}^{\circ }+{\cos }^2{65}^{\circ }}\right)$

We know that, $\cos a=\sin ({90}^{\circ }-a)$

$\Rightarrow \cos {65}^{\circ }=\sin {25}^{\circ }$

$\therefore$ Distance $=a$