What is the fourth term of the sequence a1=m an= 2an-1

Mathematics

1 answer:

kompoz [17]3 years ago

6 0

Answer:

Step-by-step explanation:

We assume you're describing a geometric sequence with first term m and common ratio 2. Then the n-th term is ...

a[n] = m·2^(n-1)

and the fourth term is

a[4] = m·2^(4-1) = 8m

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Answer:

Step-by-step explanation:

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case~2

$if~x < 0\\8x^2-5 < 120x\\8x^2-120x < 5\\x^2-15x < \frac{5}{8} \\adding~(-\frac{15}{2} )^2\\(x-\frac{15}{2} )^2 < \frac{5}{8} +(-\frac{15}{2} )^2\\|x-\frac{15}{2} | < \frac{5+450}{8} \\-\sqrt{\frac{455}{8} } < x-\frac{15}{2} < \sqrt{\frac{455}{8} } \\\frac{15}{2} -\sqrt{\frac{455}{8} } < x < \frac{15}{2} +\sqrt{\frac{455}{8} } \\but~x < 0\\7.5-\sqrt{\frac{455}{8} } < x < 0$