What is the domain and range of this function?

F(x) = log Λ―5(x-2) +1

A. Domain: x> -2; range; all positive real numbers.

B. Domain: x>2; range: all positive real numbers

C. Domain: x>-2; range: all real numbers

D. Domain; x>2; range: all real numbers

Respuesta :

As for the domain, the only restriction comes from the logarithm. The argument of a logarith must be strictly positive, so we have

[tex] x-2>0 \iff x>2[/tex]

As for the range, we have:

  • The range of [tex]\log(x)[/tex] are all real numbers
  • If we change to [tex]\log(x-2)[/tex] we're translating the function horizontally, so the range remains the same
  • If we change to [tex]\log(5(x-2()[/tex] we're stretching the function horizontally, so the range doesn't change
  • If we change to [tex]\log(5(x-2))+1[/tex] we're translating the function 1 unit up, but the range is already all the real numbers, so it doesn't change.