Is x = -2 a function?

yes

Step-by-step explanation:

No

Step-by-step explanation:

If you graph this function, you'll find that it looks like a vertical line, straight up and down. In a function, each x-value has to have exactly one y-value. In this function, however, any y-value you plug in gives you the same x-value: -2.

The one x-value, -2, has an infinite number of corresponding y-values, so this is definitely not a function.

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

i think da answer is

d.square root of 3