Final answer:
A mixed or tropical tide is created when the moon is at its maximum declination with respect to the earth, influenced by the gravitational interactions between Earth, Moon, and Sun, along with Earth's rotation and local geography.
Step-by-step explanation:
A mixed (or tropical tide) is created, according to Newton's equilibrium theory of tides, when the moon is at its maximum declination with respect to the earth. This means that a mixed tide produces a cycle consisting of one high tide and one low tide each day, and these tides are of different heights. Mixed tides occur because the path of the moon's orbit about the earth is inclined to the equator of the earth. These mixed tides are primarily the result of the gravitational interactions between the Earth, Moon, and to a lesser extent, the Sun, with the Earth's rotation and local geography further influencing the height and timing of the tides.