Since, cos-1 (a/x) – cos-1 (b/x) = cos-1 (1/b) – cos-1 (1/a)
$\text { Solve the equation: } \cos ^{-1}(a / x)-\cos ^{-1}(b / x)=\cos ^{-1}(1 / b)-\cos ^{-1}(1 / a)$
$\text { Solve the equation: } \cos ^{-1}(a / x)-\cos ^{-1}(b / x)=\cos ^{-1}(1 / b)-\cos ^{-1}(1 / a)$