1. The problem statement, all variables and given/known data Hello, I know the direct substitution property in calculus. But, the definition of a rational function still confuses me. For example, are these rational functions: y=(x^2+2x+1)/(x+1) y=((x^2+2)^(1/2))/(x+1) The denominator of the first one could cancel. So, is there still a ratio? Is it a rational function? The second one has a root in the numerator. The exponents of are not integers. Is it still a rational function? Please help me. I do not understand the definition.