[" 20.The domain of definition of "f(x)=(log_(2)(x+3))/(x^(2)+3x+2)" is: "],[qquad [" (a) "(-3,-2)" (b) "(-2,-1](c)(-3,oo)-{-1,-2}" ( "d)[0,oo)],[" 21.The domain of "f(x)=2sin x+3cos x+4" is: "],[" (a) "R" (b)R+ "(c)R-{0}(d)R-{n pi n in I^(+)}],[" 22.The domain of the function "y=sqrt(log(1)/(1" sin ")" is: ")]]