Arithmetic Sequences & Series - nth Term Calculation
Determine the 10th term of an arithmetic sequence using the nth term formula. Find missing terms and means in the sequence. Write equations for nth terms.
Arithmetic Sequences & Series - nth Term Calculation
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nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below.
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence.
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d a10 = a1 + (10 – 1)d
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d a10 = 55 + (10 – 1)d
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d a10 = 55 + (10 – 1)(-6)
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d a10 = 55 + (10 – 1)(-6)
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d a10 = 55 + (10 – 1)(-6) a10 = 55 + (9)(-6)
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d a10 = 55 + (10 – 1)(-6) a10 = 55 + (9)(-6) a10 = 55 – 54
nth Term of an Arithmetic Sequence: an = a1 + (n – 1)d Ex. 1Determine the following using the table below. a) Find the 10th term in the sequence. an = a1 + (n – 1)d a10 = 55 + (10 – 1)(-6) a10 = 55 + (9)(-6) a10 = 55 – 54 a10 = 1
b) Write an equation for the nth term of the sequence. an = a1 + (n – 1)d
b) Write an equation for the nth term of the sequence. an = a1 + (n – 1)d an = 55 + (n – 1)(-6)
b) Write an equation for the nth term of the sequence. an = a1 + (n – 1)d an = 55 + (n – 1)(-6) an = 55 - 6(n – 1)
b) Write an equation for the nth term of the sequence. an = a1 + (n – 1)d an = 55 + (n – 1)(-6) an = 55 - 6(n – 1) an = 55 - 6n + 6
b) Write an equation for the nth term of the sequence. an = a1 + (n – 1)d an = 55 + (n – 1)(-6) an = 55 - 6(n – 1) an = 55 - 6n + 6 an = - 6n + 61
b) Write an equation for the nth term of the sequence. an = a1 + (n – 1)d an = 55 + (n – 1)(-6) an = 55 - 6(n – 1) an = 55 - 6n + 6 an = - 6n + 61
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 ***Find the missing terms in the sequence!
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 an = a1 + (n – 1)d
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 an = a1 + (n – 1)d -1 = 24+ (6 – 1)d
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 an = a1 + (n – 1)d -1 = 24+ (6 – 1)d -1 = 24 + 5d -25 = 5d -5 = d
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 an = a1 + (n – 1)d -1 = 24+ (6 – 1)d -5 = d a1 = 24
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 an = a1 + (n – 1)d -1 = 24+ (6 – 1)d -5 = d a1 = 24 a2 = 24 + (-5) = 19
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 an = a1 + (n – 1)d -1 = 24+ (6 – 1)d -5 = d a1 = 24 a2 = 24 + (-5) = 19 a3 = 19 + (-5) = 14
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 d = -5 a1 = 24 a2 = 24 + (-5) = 19 a3 = 19 + (-5) = 14 a4 = 14 + (-5) = 9
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 d = -5 a1 = 24 a2 = 24 + (-5) = 19 a3 = 19 + (-5) = 14 a4 = 14 + (-5) = 9 a5 = 9 + (-5) = 4
Ex. 2 Find the arithmetic means in the sequence below. 24, ___, ___, ___, ___, -1 a1a2a3a4a5a6 n = 6 a1 = 24 a6 = -1 d = -5 a1 = 24 a2 = 24 + (-5) = 19 a3 = 19 + (-5) = 14 a4 = 14 + (-5) = 9 a5 = 9 + (-5) = 4
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following:
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d] OR Sn = ½n[ a1 + an ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following:
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following: a) a1= 58, an = -7, n = 26
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following: a) a1= 58, an = -7, n = 26
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following: a) a1= 58, an = -7, n = 26 Sn = ½n[ a1 + an ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following: a) a1= 58, an = -7, n = 26 Sn = ½n[ a1 + an ] Sn = ½(26)[ 58- 7 ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following: a) a1= 58, an = -7, n = 26 Sn = ½n[ a1 + an ] Sn = ½(26)[ 58 - 7 ] Sn = ½(26)[ 51 ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following: a) a1= 58, an = -7, n = 26 Sn = ½n[ a1 + an ] Sn = ½(26)[ 58 - 7 ] Sn = ½(26)[ 51 ] Sn = 13[ 51 ]
Sum of an Arithmetic Series The sum Snof the first n terms of an arithmetic series is given by the following: Sn = ½n[ 2a1 + (n – 1)d ] OR Sn = ½n[ a1 + an ] Ex. 3 Find Snfor each of the following: a) a1= 58, an = -7, n = 26 Sn = ½n[ a1 + an ] Sn = ½(26)[ 58 - 7 ] Sn = ½(26)[ 51 ] Sn = 13(51) = 663
Ex. 416 ∑ (4k – 2) k = 1
Ex. 416 ∑ (4k – 2) k = 1 n = 16
Ex. 416 ∑ (4k – 2) k = 1 n = 16 a1= 4(1) – 2 = 2
Ex. 416 ∑ (4k – 2) k = 1 n = 16 a1= 4(1) – 2 = 2 an= 4(16) – 2 = 62