Which relation is a function?

Only the one on the bottom left, the one that looks like the absolute value function, is a function.  The others fail the vertical line test; to be a function every vertical line must intersect the curve at at most a single point.

bottom left

the 3rd option is right

step-by-step explanation:

for this case we have by definition, if two lines are perpendicular, then the product of their slopes is -1.

then, given the following line:

so,

we are looking for m_ {2}:

then, the line is given by:

we find "b" replacing the given point:

finally, the equation is:

option c