From the definition of a function, a function associates every element of the domain to a unique element in the codomain.
In other words, if two elements are equal in the domain, then their images should also be equal.
Since, x represents the number of cars, we consider the universal set as N, the set of all natural numbers.
Let x, y ∈ N and x = y
Then, 0.75x = 0.75y
⇒ f(x) = f(y)
Therefore, images are equal, whenever elements are equal.
Hence, the function f(x) = 0.75x is a function. Also, note that the domain of the function is the set of all natural numbers and the range is the set of real numbers.
The current is doubled. Ohm's law states that V = IR, therefore, if the voltage is doubled, aka 1.5 to 3V, than assuming resistance stays constant, the current must double.
0+12, 11+1, 4x3, 6x2, etc.
