The slides from today’s lesson are here.
The homework:
For each sequence find a) the nth term formula and b) the 10th term:
1. 2, 7, 12, 17…
2. 8, 15, 22, 29…
3. 20, 17, 14, 11…
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Mr Brewin’s Year 8 – Sequences Homework26 comments to Mr Brewin’s Year 8 – Sequences Homework |
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Hey Mr B!
I was wondering how to do question 3. I know you have to subtract 3 each time, but I’m not sure how to put this in a formula!
(Help!)
Nina
Hi Nina,
If the numbers are going down in 3s then it is your -3 times table you need. However, the sequence starts with 20 not -3 so you’ll have to work out how to adjust it.
Hope that helps.
Mrs T
What she said
Thanks. I now know what I am trying to do, but I’m not sure how to put pen to paper!
How would I show that it starts at 20?
Well, if you think about the first one on the homework, you should have got 5n – 3… the -3 bit coming from what you do to the 5 times table to get 2 as your first number.
So if you’re looking at the -3 times table (-3, -6, -9…), and you need it to start at 20… well, you’re going to have to add quite a lot to get up to 2o. Helpful?
So would it be -3n+20?
(but would that mean that you start the first one at (-3n x O)+ 20, but didn’t you say in the lesson that you coulnt start a sequence with timesing O?)
Well, as you say, that would get you started at 17, not 20…
AAHHH!
I’m confuzzled!
Here’s another example:
14, 12, 10…
Based on -2 times table. But the -2′s go:
-2, -4, -6…
So to get this to start at 14, we have to add 16
So it’d be -2n + 16
Now try with the one above…
so mine would be -3n + 23! (Am I right or wrong?)
That’s right Nina – well done
Yay!
Go me!
Thank you for your help!
All part of the service!
Now will you stop drawing on my arm?
Thanks Nina
You gave me the answer!!!!
lol
Pia
Its OK Pia
No Mr B I will not stop drawing on your arm, and as you said ‘it is all part of the service’
HA!
Now its my turn to be confuzzled
How is Nina drawing on your arm
:s …..
haha
Pia
HELP
The slides won’t load on my computer so it is a bit hard for me to copy up as the bell went when i was doing it… I must admit I’m a bit slow
how can i get them to load because it keeps on coming up with the error message with the don’t send thing if you get what i mean …
Pia
Hi Pia,
Don’t know if this will work, but if you RIGHT click on where Mr B has put ‘here’ then you should get the option to ‘save target as’. If you save it on your own desktop, it might open OK.
Mrs T
Oh its alright
I fixed it because i am amazing
I really am actually
I’m a genius
Bye
By the way I just switched computers
Pia
But thanks anyway Mrs T
Pia
Mr Brewin
I was wondering are we having a moc exam on thursday. Will we need to know about pi and finding the circumference of a circle?
HI KATE
I’M BORED
MERRY XMAS
but i don’t understand sig figs
Help !!
Happy Christmas Pia
Start counting from the first ‘real’ number
eg in 4090.87653, the 1st sig fig is the 4
and in 0.000409087653 it is still the 4.as the zeros are just there for place value purposes – to keep the significant numbers in the right columns.
Does that help?
Mrs Tea
Thankyou
I get it now !!