Given a geometric sequence with a 3= 20 and a 8= 640, find a 1 and r

Q: a5 = -15 and a13 = -55 Find for the arithmetic sequence above: a21 =

A: Given:  a5=-15 and a13=-55 To Find:  To find a21 for the above arithmetic sequence.

Q: In the arithmetic sequence, to= 166 and t12= 130, find the nth term

A: We know, the n-th term of an Arithmetic sequence is given by the formula : tn=a+(n-1)d,where,a=…

Q: For the arithmetic sequence, find and when a1 4 and d = - 5. %3D a11 an a11 -

A: first term a1 = 4 common difference d =-5

Q: zu 00{ " + uc}

A:

Sequence and Series

A sequence is defined as a collection of things. Series is defined to sum the things one by one in the sequence.  It was invented by German mathematician Carl Friedrich Gauss.