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.
Aside from those guidelines, you can prune your crepe myrtle to a shape and size that works for your yard. 1  Crepe myrtles can grow about 1 to 2 feet (30-40 cm) per season, so prune based on your desired tree height.