Astrological sign of a sign are together sufficient to define it, they can be grouped to indicate their symbolism. The first four signs, Aries, Taurus, Gemini and Cancer, form the group of personal signs. The next four signs, Leo, Virgo, Libra and Scorpio form the group of interpersonal signs. The last four signs of the zodiac, Sagittarius, Capricorn, Aquarius and Pisces, form the group of transpersonal signs. Dane Rudhyar presented the tropical zodiac primary factors, used in the curriculum of the RASA School of Astrology. The tropical zodiac is the zodiac of seasonal factors as opposed to the sidereal zodiac (constellation factors).
Plus-minus sign be rewritten as ""x" ± ("y" − "z")" to avoid confusion, but cases such as the trigonometric identity are most neatly written using the "∓" sign. The trigonometric equation above thus represents the two equations: but "not" because the signs are exclusively alternating. Another example is which represents two equations. The plus-minus sign resembles the Chinese characters and , whereas the minus-plus sign resembles . Plus-minus sign The plus-minus sign (±) is a mathematical symbol with multiple meanings. The sign is normally pronounced "plus or minus" or "plus-minus". A version of the sign, including also the French word "ou" ("or")