<u>x-3 </u> ≥ 0
x+3
x+3≠0
x≠-3
<u>x-3 </u>≥0
x+3
(x-3)(x+3)≥0
x=3 x=-3
+ - +
---------- -3 ------------ 3 ----------------
\\\\\\\\\\\ \\\\\\\\\\\\\\\\
x∈(-∞; -3)U[3; +∞)
D(y)=(-∞; -3)U[3; +∞) - область определения функции.
Sin(45-b)+sin(45+b)=sin45cosb-sinbcos45+<span>sin45cosb+sinbcos45=2sin45cosb=2cosb</span>