List of Trigonometric Identities - Angle Sum and Difference Identities

Angle Sum and Difference Identities

See also: #Product-to-sum and sum-to-product identities

These 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:

    From whichever angle one looks at it, the application of racial theories remains a striking proof of the lowered demands of public opinion upon the purity of critical judgment.
    Johan Huizinga (1872–1945)

    We didn’t come to dig in Egypt for medals. Much more is learned from studying bits of broken pottery than from all the sensational finds. Our job is to increase the sum of human knowledge of the past, not to satisfy our own curiosity.
    John L. Balderston (1899–1954)

    There it is: it doesn’t make any difference who we are or what we are, there’s always somebody to look down on! somebody to hold in light esteem, somebody to be indifferent about.
    Mark Twain [Samuel Langhorne Clemens] (1835–1910)