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.
Seeing a crepe myrtle in its full summer splendor sends some of us running to the garden shop to buy a plant the same color. But don't buy impulsively. Pay attention to the plant's tag. Make sure that it is not only the exact color that you want, but also the right size and look you hope to achieve.