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.
How Fast Will Crape Myrtles Grow? Crape myrtle, often called the lilac of the South, is a shrub or tree suitable for many landscape settings. Crape myrtle produces clusters of red, white, pink or purple flowers in summer, followed by brown fruit pods that remain on the plant through the winter.