28(sin^2 23-cos^2 23)/cos 46

[latex] \frac{28( sin^{2}(23)- cos^{2}(23)) }{cos(46)} [/latex]= [latex] \frac{-28*( cos^{2}(23)- sin^{2}(23)) }{cos(46)} [/latex]= [latex] \frac{-28*cos(46)}{cos(46)} [/latex]= - 28 Ответ: - 28