Solution: Let’ s draw arrow diagram. We can see that for every element of set A, it has only 1 image / output in set B. Thus it is a function.
Real & Real Valued functions
Real Value function: Range à R or subset of R( that is output is R but not input)
Real function: Both range & domain à R or subset of R
Graph of identity function, f( x) = x, is a straight line. Domain = R & Range = R.