Б
f(x)=log(3)(tgπ/3)=log(3)√3=1/2
г
f(x)=cos(sin√(4π²)=cos(sin2π)=cos0=1
2
(4-x²)/(x-1)>0
(2-x)(2+x)/(x-1)>0
x=2,x=-2,x=1
+ _ + _
--------------(-2)---------------(1)-------------------(2)--------------------
x∈(-∞;-2) U (1;2)
3
{x+3>0⇒x>-3
{log(21)(x+3)≠0⇒x+3≠1⇒x≠1-3⇒x≠-2
{(5-x)(5+x)≥0⇒-5≤x≤5
////////////////////////////////////////////
----------[-5]-------(-3)------(-2)----------[5]--------------
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
x∈(-3;-2) U (-2;5]