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.
A U.S. Department of Agriculture research scientist bred these beauties, and now they are grown by J. Berry Nursery in Texas. Five in series. The stunning black diamond crape myrtle has five different colors. We all know how different reds can be, and there is the Best Red, which is a very dark red. You might think it wouldn't show up with the dark burgundy leaves, but it is a beautiful mix of colors.
Crepe Myrtle Trees: Colorful Ornamental Trees Increase Property Value. Landscapers and homeowners choose to plant Crepe Myrtle when a splash of color is needed. These small to medium sized trees provide glamorous colors from late spring to late summer. Best planted in the warmer locations of the United States, Crepe Myrtles prefer USDA Hardiness Zones 6 to 10.