i need help

Which function has an inverse that is also a function?
g(x) = 2x – 3
k(x) = –9x2
f(x) = |x + 2|
w(x) = –20

Question

i need help

Which function has an inverse that is also a function?
g(x) = 2x – 3
k(x) = –9x2
f(x) = |x + 2|
w(x) = –20

Echofire · Answer

To find an inverse of a function, switch the variables and solve in terms of x. Remember, the inverse function has to pass the vertical line test. The last option is a constant so it has no inverse and the 3rd option can be ruled out because absolute value functions do not have an inverse. I assume the k(x) function is -9x^2. Find and graph the inverse of the remaining functions and you will find the answer and see why it makes sense that it is the answer.