How do you find the domain of # f(x)=x+2 #?

2 Answers
Apr 6, 2017

By inspection:-


There is no real value of #x# at which f(#x#) is not defined.
Thus , the Domain of this Function is set of all Real Numbers.
Moreover, this is the equation of a straight line having Gradient = 1 with #x# and #y# intercepts as -2 and 2 respectively.

Apr 6, 2017

See explanation.


To find the domain of a function you have to look for the largest subset of all real numbers for which the function is defined.

Usually to find the domain you think of all values excluded from it (this is the values of #x# for which the function is not defined). Such values can be searched among:

  • the zeros of the denominators,

  • values for which the expressions under square root sign are negative,

  • values for which the expressions under logarythm sign are negative.

In the given function there are NO such exclusions, so the domain is the whole set of real numbers: