Question

Let f(x) = 3x ­- 6 and g(x) = x ­- 2. Find f(g(5)) - ie. (f o g)(5) and its domain

1; all real numbers

3; all real numbers except x = 3

3; all real numbers except x = 2

3; all real numbers

Answer 1

Do this by finding g(5) first. Replacing x with 5 in g(x) gives you that g(5) = 3. Now replace that 3 in the x in f(x) to get that f(3) = 3. As far as the domain goes,, they are both lines and the domain for lines is all real numbers.