A) $ -2 $
B) $ -1 $
C) $ 0 $
D) $ 1 $
Correct Answer: C
$ \Rightarrow $ $ 25(1-{{\cos }^{2}}\theta )+144(1-{{\sin }^{2}}\theta ) $ $ +120\sin \theta \cos \theta =169 $
$ \Rightarrow $ $ 25-25{{\cos }^{2}}\theta +144-144{{\sin }^{2}}\theta $ $ +120\sin \theta \cos \theta =169 $
$ \Rightarrow $ $ 25{{\cos }^{2}}\theta +144{{\sin }^{2}}\theta -120\sin \theta \cos \theta =169-169 $
$ \Rightarrow $ $ {{(5\cos \theta -12\sin \theta )}^{2}}=0 $
$ \Rightarrow $ $ 5\cos \theta -12\sin \theta =0 $