 The sum of a series of quantities in arithmetical progression is found by multiplying the sum of the first and last terms by half the number of terms.  Algebra Self-taught - 77. lappuseautors: W. P. Higgs - 1876 - 104 lapasPilnskats - Par šo grāmatu
 | William Nicholson - 1809 - 684 lapas
...the nlh or last term. • " The sum of a series of quantities in arithmetical progression is found by multiplying the sum of the first and last terms by half the number of terms." Let a be the first term, b the common difference, n the number of terms, and » the sum of the series... | |
 | William Nicholson - 1821 - 376 lapas
...the «th or last lerm. " The sum of a series of quantities in arithmetical progression is found by multiplying the sum of the first and last terms by half the number of terms." Let a be the first term, A the common difference, n the number of terms, and a the sum of the series:... | |
 | James Wood - 1825 - 322 lapas
.... 6 the иlh term. (212.) The sum of a series of quantities in arithmetical progression is found by multiplying the sum of the first and last terms by half the number of terms. Let a be the first term, b the common difference, и the number of terms, and s the sum of the series:... | |
 | Etienne Bézout - 1836 - 216 lapas
...terms of this arithmetical progression. But the sum of the terms of such a progression is found by multiplying the sum of the first and last terms by half the number of terms. Whence, this sum •will be, (substituting u for its value gt, which is the last term,) (,§" + M)... | |
 | William Whewell - 1837 - 226 lapas
...#) = 9« +7.r - 5 a - 5x = 4 a + 2 a: 60. To find the sum of an arithmetical progression, multiply the sum of the first and last terms by half the number of terms. Thus the sum of 10 terms of 1, 3, 5, &C. is (1 + 19) x 5 = 100. For if l + 3 + 5 + &c. to 19 (10 terms)... | |
 | John D. Williams - 1840 - 634 lapas
...terms, we shall have CASE I. The sum of a series of quantities in arithmetical progression is found by multiplying the sum of the first and last terms by half the number of terms. Let a = first term, d = common difference, n = number of terms, and s = sum of the series. a _f- a_j_a... | |
 | John D. Williams - 1840 - 216 lapas
...terms, we shall have CASE I. The sum of a series of quantities in arithmetical progression is found by multiplying the sum of the first and last terms by half the number of terms. Let a = first term, d = common difference, n = number of terms, and s = sum of the series. a + a-\-d... | |
 | Augustus De Morgan - 1840 - 186 lapas
...as before. The rule, then, is : To sum any number of terms of an arithmetical progression, multiply the sum of the first and last terms by half the number of terms. For example, what are 99 terms of the series 1, 2, 3, &c. ? The 99th term is 99, and the sum is (99... | |
 | Thomas Sherwin - 1841 - 314 lapas
...n(a S= ^ ' — '-. Hence, M The sum of any number of terms in progression by difference, is found, by multiplying the sum of the first and last terms by half the number of terms, or by multiplying half the sum of the first and last terms by the number of terms. By substituting... | |
 | Wales Christopher Hotson - 1842 - 306 lapas
...for the last term. z Hence, the sum of a series of quantities in arithmetical progression is found by multiplying the sum of the first and last terms by half the number of terms. 160. By means of the equations I = a + (n — 1) d and s = - J2a-|-(rc — 1) d\ , any three of the... | |
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