(x - 4)^2 - 2x (x - 2) = x^2 - 8x + 16 - 2x^2 + 4x = - x^2 - 4x + 16
1)<span>y=sin x-1/2x. Y=2/x2+4 ; y=4x+8/2x +3 на (-2;3)</span>
9аб/(а+9б)*а²-(9б)²/9аб=(а-б)(а+б)/(а+б)=а-б
((cosa+cos5a)-(cos3a+cos7a))/(sina+sin5a)+(sin3a+sin7a)=
=(2cos3acos2a-2cos5acos2a)/(2sin3acos2a+2sin5acos2a)=
=2cos2a(cos3a-cos5a)/2cos2a(sin3a+sin5a)=(cos3a-cos5a)/(sin3a+sin5a)=
2sin4asina/2sin4acosa=sina/cosa=tga