(4sinA - 3cosA)² + (3sin²A + 4cos²A) = 16sin²A - 24sinAcosA + 9cos²A +
+ 9cos²A + 24sinAcosA + 16sin²A = 25sin²A + 25cos²A = 25(sin²A + cos²A) =
= 25
1,2х≥7
х≥7:1,2
х≥70/12
х≥5 5/6
х∈[5 5/6;+∞)
M=4/(4•2)=1/2;n=4•1/4-4•1/2+3=1-2+3=2-наименьшее значение
((13/30)-(11/20))*(9/5)
1. (13/30)-(11/20)=(13*2-11*3)/60=(26-33)/60=7/60.
2. (7/60)*(9/5)=63/300=0,21.
1/((1/9)-(1/12))
1. (1/9)-(1/12)=(1*4-1*3)/36=(4-3)/36=1/36
2. 1/(1/36)=36.