Which statement must be true?
a
b
c
d

Answer:
Option 1 m≠0 is the right option.
Step-by-step explanation:
In this question we will find the inverse function first then we will find the gradient of the inverse function to get the correct answer.
The given function is f(x) = mx + b
Or y = mx + b
Now we will rewrite the equation in the form of x.
y - b = mx + b - b
y - b = mx
[tex]x = \frac{1}{m}y - \frac{b}{m}[/tex]
Now we can write the inverse function as
[tex]f^{-1}(x) = \frac{x}{m} - \frac{b}{m}[/tex]
Now the gradient of the inverse function is (1/m).Therefor we can easily say that the given function is defined when m≠0 because for m = 0 gradient will be infinity.
Therefore option 1. m≠0 is the right option.