Defining the cotangent function. The cotangent function is an old mathematical function. It was mentioned in 1620 by E. Gunter who invented the notation of cotangens. Later on J. Keill (1726) and L. Euler (1748) used this function and its notation in their investigations.
Crepe Myrtles are among the toughest, most adaptable, and showiest plants that can be grown in the Texas landscape. Along with their bright colorful bloom display during the summer months the leaves of the Crepe Myrtle also turn orange, red and yellow in the fall.
There are nine main types of hibiscus blossoms, with many variations of these nine types. Even on the same bush at the same time there maybe a variation in shape and colouring. 1. Cartwheel overlap single: Petals are completely overlapped to tips giving a regular, circular appearance.