All the given statements are true.
1. The periods of the functions y=sin(x) and y=cos(x) are indeed 2π. This is because these functions repeat their values every 2π. The period of the function y=tan(x) is π, as this function repeats its values every π.
2. The graphs of y=sin(x) and y=cos(x) do not have midlines. A midline is a horizontal line that lies halfway between the maximum and minimum values of the function. These sine and cosine functions have a maximum value of 1 and a minimum value of -1, and they oscillate around the x-axis, which acts as a midline. However, since the x-axis is not part of the graph itself, we can say that these functions do not have midlines.
3. Both y=sin(x) and y=tan(x) are increasing on the interval (0, 2π). This means that as the value of x increases within this interval, so does the value of the function. In contrast, y=cos(x) is decreasing on the same interval, meaning that as x increases, the value of the function decreases.
4. The amplitudes of y=sin(x), y=cos(x), and y=tan(x) are 1. The amplitude of a function is the maximum absolute value it can reach. For the sine and cosine functions, this is indeed 1, as these functions oscillate between -1 and 1. In the case of the tangent function, it is also 1 because even though the range of the y=tan(x) is all real numbers, it reaches its maximum and minimum values at 1 and -1 respectively.
5. The domains of y=sin(x), y=cos(x), and y=tan(x) are all real numbers. This means that these functions can take any real number as input. This is indeed true for these three functions. In other words, there are no values of x for which these functions are undefined.