Math Is Fun Forum

90sginger

Member

Registered: 2016-04-20

Posts: 19

Re: Lesson 20 Sequences and Series

Hi;

Do I stop there or keep going?

You just need v5 and v6 and you are done with the first two questions.

Ah I apologize. I did that and I got:

v5 = 4/5 + 2
v5 = 4/7
v6 = 4/6 + 2
v6 = 4/8

I just need help with the other questions I posted and I'll be good!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

Do not forget to reduce v6.

What help do you need with them?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

90sginger

Member

Registered: 2016-04-20

Posts: 19

Re: Lesson 20 Sequences and Series

Do not forget to reduce v6.

What help do you need with them?

Just how to do them or if they're the same like number 1 and 2

For problems 9 and 10, write each sum using summation notation.
9.2 + 5 + 8 + 11 + ... + 29
10. 6 - 12 + 24 - 48 + ...
11. Find the sum of the arithmetic sequence 2, 4, 6, 8, ..., 70.
12. Find the sum of the geometric sequence
http://www.sc.whitmoreschool.org/sec/students/classes/scalgebra_2/lesson35_files/clip_image107.gif
For problems 13 and 14, find the sum of the first n terms of the sequence.  The sequences are either arithmetic or geometric.
13.  -1, 11, -121, ...; n = 9
14. 14, 8, 2,...; n=9
15. Determine whether the infinite series  is equal to a real number.  If so, find the sum.
http://www.sc.whitmoreschool.org/sec/students/classes/scalgebra_2/lesson35_files/clip_image121.gif

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

Hi;

No, they are different. Do you know how to use summation notation?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

90sginger

Member

Registered: 2016-04-20

Posts: 19

Re: Lesson 20 Sequences and Series

Hi;

No, they are different. Do you know how to use summation notation?

No I do not know how to use summation notation.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

Okay, it is a bit tricky at first so go here.

http://www.mathsisfun.com/algebra/sigma-notation.html

Try to get something out of that and then if you still can not tackle the problems I will do them.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

90sginger

Member

Registered: 2016-04-20

Posts: 19

Re: Lesson 20 Sequences and Series

Okay, it is a bit tricky at first so go here.

http://www.mathsisfun.com/algebra/sigma-notation.html

Try to get something out of that and then if you still can not tackle the problems I will do them.

Hi,
I cannot tackle the problems. They still confuse me.

Last edited by 90sginger (2016-04-21 12:23:41)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

You have read the page I sent you to?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

Im stuck on these questions too ! Help please, this is my last lesson in online school!
For problems 9 and 10, write each sum using summation notation.

9.2 + 5 + 8 + 11 + ... + 29

10. 6 - 12 + 24 - 48 + ...

11. Find the sum of the arithmetic sequence 2, 4, 6, 8, ..., 70.

12. Find the sum of the geometric sequence 42, 7 , 7/6,...,42(1/6)^8

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

Hi;

One way for 9) is:

One way for 10) is:

11) 1260

12) I am getting

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

Gosh thank you so much bobbynm. I have a few more questions as well.

These are confusing me too

For problems 13 and 14, find the sum of the first n terms of the sequence.  The sequences are either arithmetic or geometric.

13.  -1, 11, -121, ...; n = 9

14. 14, 8, 2,...; n=9

15. Determine whether the infinite series   is equal to a real number.  If so, find the sum.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

Hi;

15) Which series?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

i didn't mean to put 15 in there, but now i'm doing a revision for Lesson 16 and it's asking me to solve the matrix equation for X:

How would I do that.

[[  6   -3 
    7    9 ]] X =  [[ -18   -93 
                            4      -21 ]]

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

Hi;

I still do not see the series for 15).

For your new problem.

Can you take it from here or do you need more help?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

[[ -3, 31
   0.57, -2.33]]

Is that correct ?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

I am not getting that, please try again.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

90sginger

Member

Registered: 2016-04-20

Posts: 19

Re: Lesson 20 Sequences and Series

You have read the page I sent you to?

Hi, sorry for the late reply, I was sick. Yes, I read the page and tried the best I can but I couldn't understand or was very confused on what to do.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

I need assistance, how do i do that ?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

What did you get when you did

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

I am lost what do i multiply, do i multiply
(6*6) (-3*-3) (7*7) (9*9)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

They have not taught you how to multiply 2 matrices?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

Not really, since i am an online student, they don't really teach they just give you the lesson and expect you to know everything.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

This is your last lesson, do you want the answer to this?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Lpravia020614

Member

Registered: 2015-11-03

Posts: 35

Re: Lesson 20 Sequences and Series

My last lesson is lesson 20 however i completes that lesson on my own, it was easy. This lesson is #16 and its very confusing. there are 20 questions per lesson and i answer 1-10 correctly but when i attempted 11-20 i got the ALL wrong. i dont know how to do this, it is causing me to fall behind. so yeas i would enjoy an answer to this.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Lesson 20 Sequences and Series

I will post the answer in about a half hour. Is that okay?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.