$\begin{array}{l} \dfrac{{{{\cot }^2}x - {{\cos }^2}x}}{{{{\cot }^2}x}} + \dfrac{{\sin x\cos x}}{{\cot x}}\\ = 1 - \dfrac{{{{\cot }^2}x.{{\sin }^2}x}}{{{{\cot }^2}x}} + \dfrac{{{{\sin }^2}x\cot x}}{{\cot x}}\\ = 1 - {\sin ^2}x + {\sin ^2}x = 1\\ B = 1994\left( {{{\sin }^6}x + {{\cos }^6}x} \right) - 2991\left( {{{\sin }^4}x + {{\cos }^4}x} \right)\\ \Rightarrow \dfrac{B}{{997}} = 2\left( {{{\sin }^6}x + {{\cos }^6}x} \right) - 3\left( {{{\sin }^4}x + {{\cos }^4}x} \right)\\ \Rightarrow \dfrac{B}{{997}} = 2\left( {{{\sin }^2}x + {{\cos }^2}x} \right)\left( {{{\sin }^4}x - {{\sin }^2}x{{\cos }^2}x + {{\cos }^4}x} \right) - 3\left[ {{{\left( {{{\sin }^2}x + {{\cos }^2}x} \right)}^2} - 2{{\sin }^2}x{{\cos }^2}x} \right]\\ \Rightarrow \dfrac{B}{{997}} = 2\left( {1 - 3{{\sin }^2}x{{\cos }^2}x} \right) - 3\left[ {1 - 2{{\sin }^2}x{{\cos }^2}x} \right] = - 1\\ \Rightarrow B = - 997\\ C = \dfrac{{\sin {{32}^o}}}{{\cos {{58}^o}}} - \left( {\tan {{76}^o} - \cot {{14}^o}} \right)\\ C = \dfrac{{\cos {{58}^o}}}{{\cos {{58}^o}}} - \left( {\tan {{76}^o} - \tan {{76}^o}} \right)\\ C = 1 - 0 = 1 \end{array}$
