Помогите решить пожалуйста!) 1)45 / sin( – 25 × π / 4) × cos(35 × π / 4) 2)4 × sin(130°) / sin(65°) × sin(25°) 3)– 14 × sin(58°) / cos(29°) × cos(61°) 4)tg^2-? 4sin^2a+10cos^2a=9

1)45 / sin( – 25 × π / 4) × cos(35 × π / 4) =45/(-sin(6π+π/4)*cos(9π-π/4))= =45/(-sinπ/4*(-cosπ/4)=90/sinπ/2=90 2)4 × sin(130°) / sin(65°) × sin(25°) =4sin(180-50)/(sin(90-25)sin25)= =4sin50/(cos25sin25)=8sin50/sin50=8 3)– 14 × sin(58°) / cos(29°) × cos(61°) =-14sin58/(cos29cos(90-29))= =-14sin58/(cos29sin29)=-28sin58/sin58=-28 4)tg^2-? 4sin^2a+10cos^2a=9 4sin²a+10-10sin²a=9 6sin²a=1 sin²a-1/6 cos²a=1-sin²a=1-1/6=5/6 tg²a=sin²a/cos²a=1/6:5/6=1/6*6/5=1/5