MathematicsMedium38×since 2002Q3589If dydx+3cos2xy=1cos2x, x∈(−π3,π3){{dy} \over {dx}} + {3 \over {{{\cos }^2}x}}y = {1 \over {{{\cos }^2}x}},\,\,x \in \left( {{{ - \pi } \over 3},{\pi \over 3}} \right)dxdy+cos2x3y=cos2x1,x∈(3−π,3π) and y(π4)=43,y\left( {{\pi \over 4}} \right) = {4 \over 3},y(4π)=34, then y(−π4)y\left( { - {\pi \over 4}} \right)y(−4π) equals -A13+e6{1 \over 3} + {e^6}31+e6B13{1 \over 3}31C13{1 \over 3}31 + e³D−-− 43{4 \over 3}34Check answerSkip