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Daily Check 1)Find the first 3 terms of the following sequence: 2)Write the formula for the following arithmetic sequence. -2, 1, 4, 7, 10
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EOCT Practice Which expression represents the sum of the first n multiples of 8? c a)8n b)8n 2 c)4n 2 + 4n d)8n 2 + 8n
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EOCT Practice Alex started a business making bracelets. Her goal is to sell 6 more bracelets each month than she sold the previous month. If Alex meets her goal, what is the total number of bracelets she will sell in the first 12 months? d a)378 b)426 c)498 d)756
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Math II UNIT QUESTION: How is a geometric sequence like an exponential function? Standard: MM2A2, MM2A3 Today’s Question: How is a geometric sequence like an exponential function? Standard: MM2A3f,g
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Sequences and Series
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Geometric Sequences In geometric sequences, you multiply by a common ratio each time. 1, 2, 4, 8, 16,... multiply by 2 27, 9, 3, 1, 1/3,... Divide by 3 which means multiply by 1/3
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Geometric Sequences Find the 8 th term of the sequence: 2,6,18,… Determine the pattern: Multiply by 3 (known as the common ratio) Write the new sequence: 2,6,18,54,162,486,1458,4374 So the 8 th term is 4374.
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Geometric Sequences Again, use a formula to find large numbers. a n = a 1 (r) n-1
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Geometric Sequences Find the 10 th term of the sequence : 4,8,16,… a n = a 1 (r) n-1 a 1 = 4 r = 2 n = 10
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Geometric Sequences a n = a 1 (r) n-1 a 10 = 4 (2) 10-1 a 10 = 4 (2) 9 a 10 = 4 512 a 10 = 2048
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Geometric Sequences Find the ninth term of a sequence if a 3 = 63 and r = -3 a 1 = ? n= 9 r = -3 a 9 = ? There are 2 unknowns so you must…
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Geometric Sequences First find t 1. Use the sequences formula substituting t 3 in for t n. a 3 = 63 a 3 = a 1 (-3) 3-1 63 = a 1 (-3) 2 63= a 1 9 7 = a 1
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Geometric Sequences Now that you know t 1, substitute again to find t n. a n = a 1 (r) n-1 a 9 = 7 (-3) 9-1 a 9 = 7 (-3) 8 a 9 = 7 6561 a 9 = 45927
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Class work Coach Book Page 93 and 94
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Homework Page 145 #2-16 (even)
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