\({R_{\min }} = A - B = 7\) when \(\theta = 180^\circ \)
by solving we get \(A = 12\) and \(B = 5\)
Now when \(\theta = 90^\circ \) then \(R = \sqrt {{A^2} + {B^2}} \)
\(⇒\) \(R = \sqrt {{{(12)}^2} + {{(5)}^2}} \)\( = \sqrt {169} \)\( = 13\)
$\left(\cos 135^{\circ}=-0.7\right.$ આપેલ છે.)
$\left(\cos 135^{\circ}=-0.7\right.$ આપેલ છે.)