In the quadratic function f(d) = -0.6dxd + 5.4d + 0.8 where d is the horizontal distance that a ball travels in yards, and f(d) is the height, in yards, of the ball at d horizontal yards. What would be the total horizontal distance the ball travels while in the air?

Horizontal distance, d = 9.146

Step-by-step explanation:

The given function is

The horizontal distance, d, is the distance on ground. So, set f(d) = 0.

That is, a height of zero which becomes the ground level.

Using the quadratic formula:

Thus, the ball is in air between d=-0.146 to d=9.146.

Since the distance can not be negative, the ball remains in the air between d = 0 to d = 9.146.

Therefore d = 9.146

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.