fourth grade math terms

Let a = First term, r = common ratio, n = number of terms. Multiply both sides of (i) by r, the common ratio. Subtracting (ii) from (i), we get ..

Let a=first term, d = common difference, l=t n =last term, s = required sum. Then, Writing the series in the reverse order, Adding together the two series, ..

i) 1 + 4 + 7 + 10 + ... is a series in which first term is 1, second term is 4, third term is 7 and so on. ii) 3 - 9 + 27 - 81 + ... is also a series in which the first term is 3, second term is -9, third term is 27 an..

2, 5, 8, 11, 14 , 32 37, 33 , 1 A sequence is called infinite if the number of terms is infinite. An infinite sequence has no last term. In this sequence, every term is followed by a new term..

Geometric Progressions (G.P.) - The series of terms a, ar, ar 2 , ar 3 ,.... in which each term bears a constant ratio to the preceeding term is a geometric progression. The constant ratio is called the common ratio.OR A geometrical progression is a succession of ..

The series of terms a, ar, ar 2 , ar 3 ,.... in which each term bears a constant ratio to the preceeding term is a geometric progression. The constant ratio is called the common rati..

i) The series formed by the reciprocals of the terms of a geometric series is also a geometric series. ii) There is no general method of finding the sum of a harmonic progressi..

1. Find the sum to the series 1+2x+3x 2 +.... to n terms and to infinity when x < ..

If D = 0 and all D 1 , D 2 and D 3 are zeros, this system has either infinite solution or no solution. In this case, put x = k(y = k or z = k), in any two of the equations, find y and z in terms of k. Substitute these values of x, y and z in terms of k, in the third equation...

Harmonic Mean (H.M.) - If three quantities are in harmonic progression, then the middle quantity is called the harmonic mean between the other two. Example: 1/3, 1/7, 1/11 are in H.P., then 1/7 is the middle term. Hence 1/7 is the harmonic mean between 1/3 and 1/1..