Find the next two terms in the given sequence, then write it in recursive form. A.) {7,12,17,22,27,...} B.) { 3,7,15,31,63,...}
iren [92.7K]
Answer:
A) a_n = 5n + 2
B) a_n = (2^(n + 1)) - 1
Step-by-step explanation:
A) The sequence is given as;
{7,12,17,22,27,...}
The differences are:
5,5,5,5.
This is an arithmetic sequence following the formula;
a_n = a_1 + (n - 1)d
d is 5
Thus;
a_n = a_1 + (n - 1)5
Now, a_1 = 7. Thus;
a_n = 7 + 5n - 5
a_n = 5n + 2
B) The sequence is given as;
{ 3,7,15,31,63,...}
Now, let's write out the differences of this sequence:
Differences are:
4, 8, 16, 32
This shows that it is a geometric sequence with a common ratio of 2.
In the given sequence, a_1 = 3 and a_2 = 7 and a_3 = 15
Thus, a_2 = 2a_1 + 1
Also, a_(2 + 1) = 2a_2 + 1
Combining both equations, we can deduce that: a_(n + 1) = 2a_n + 1
Thus; a_n can be expressed as:
a_n = (2^(n + 1)) - 1
Rachel spends 6 hours 45 minutes a week trying to learn to play the violin.
Step-by-step explanation:
Step 1; Rachel learns for 45 minutes a day from Monday through Friday and in the weekend she learns to play the violin for one and a half hours. So she learns for the following periods of time
Monday - 45 minutes
Tuesday - 45 minutes
Wednesday - 45 minutes
Thursday - 45 minutes
Friday - 45 minutes
Saturday - 90 minutes (60 × 1.5 hours)
Sunday - 90 minutes (60 × 1.5 hours)
Step 2; To determine how much time she practices in a week we just add the individual times she plays on each day.
Total time practices in a week = 45 + 45 + 45 + 45 + 45 + 90 + 90 = 405 minutes = 6 hours 45 minutes.
Answer:
i think it is the last one.
I don’t see a point so how am I supposed to answer
Answer:
6
Step-by-step explanation: