Final answer:
An even function exhibits symmetry about the y-axis. To show that a function is even, we need to prove that y(x) = y(-x) for all values of x. In the given equation y = P(x), we substitute -x for x and show that the equation holds.
Step-by-step explanation:
An even function is a type of function that exhibits symmetry about the y-axis. This means that if we reflect the function across the y-axis, the graph remains unchanged. The algebraic definition of an even function is y(x) = y(-x). To show that a function is even, we need to prove that y(x) = y(-x) for all values of x.
In this case, the equation for y = P(x) is y(x) = −y(-x). To show that P(x) is an even function, we substitute -x for x in the equation and simplify:
y(-x) = −y(-(-x))
y(-x) = −y(x)
Since y(x) = −y(-x) holds for all values of x, we can conclude that P(x) is an even function.