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.
It flowers and makes you gasp. 1  Crepe myrtle are deciduous or evergreen, flowering trees or shrubs and are among the best flowering trees. 2  Crepe myrtle is also known as the crape myrtle, and its scientific name is Lagerstroemia.