[MOVED] 'If f is one-to-one' question

[killasnake]

How would I solve this?

If f is one-to-one and f^-1 (-12) = 7 then,

f^-1 (7) = -12

and (f(-12))^-1= ______

How do I solve for (f(-12))^-1? woudn't the asnwer be -7?

 

[tkhunny]

You MUST differentiate clearly between the reciprocal of f(x) -- \(\displaystyle (f(x))^{-1}\) -- and the inverse of f(x) -- \(\displaystyle f^{-1}(x)\). I am not confident you have made the distinction. Check the problem carefully and verify that you have it straight.

 

[skeeter]

If f is one-to-one and f^-1 (-12) = 7 then,

f^-1 (7) = -12

and (f(-12))^-1= ______

How do I solve for (f(-12))^-1? woudn't the asnwer be -7?

NO.

if f^-1(-12) = 7, and f is 1-1, then f(7) = -12.

[f(-12)]^-1 = 1/f(-12) ... it has nothing to do with inverses. You do not have enough information to determine f(-12).