Angle Sum and Difference Identities
See also: #Product-to-sum and sum-to-product identitiesThese are also known as the addition and subtraction theorems or formulæ. They were originally established by the 10th century Persian mathematician Abū al-Wafā' Būzjānī. One method of proving these identities is to apply Euler's formula. The use of the symbols and is described in the article plus-minus sign.
| Sine | |
|---|---|
| Cosine | |
| Tangent | |
| Arcsine | |
| Arccosine | |
| Arctangent |
Read more about this topic: List Of Trigonometric Identities
Famous quotes containing the words angle, sum and/or difference:
“Modesty is the only sure bait when you angle for praise.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“They are but beggars that can count their worth,
But my true love is grown to such excess
I cannot sum up sum of half my wealth.”
—William Shakespeare (1564–1616)
“There is a difference between a book of two hundred pages from the very beginning, and a book of two hundred pages which is the result of an original eight hundred pages. The six hundred are there. Only you don’t see them.”
—Elie Wiesel (b. 1928)