MathematicsMedium63×since 2002Q3670If y(α)=2(tanα+cotα1+tan2α)+1sin2α,α∈(3π4,π)y\left( \alpha \right) = \sqrt {2\left( {{{\tan \alpha + \cot \alpha } \over {1 + {{\tan }^2}\alpha }}} \right) + {1 \over {{{\sin }^2}\alpha }}} ,\alpha \in \left( {{{3\pi } \over 4},\pi } \right)y(α)=2(1+tan2αtanα+cotα)+sin2α1,α∈(43π,π) dydα at α=5π6is{{dy} \over {d\alpha }}\,\,at\,\alpha = {{5\pi } \over 6}isdαdyatα=65πis :A4B-4C43{4 \over 3}34D-14{1 \over 4}41Check answerSkip