Math Is Fun Forum

Lea2007

Member

Registered: 2007-01-18

Posts: 1

Newbie, needing urgent help please

Hi All:) , I have a maths problem, that I don't understand, I would be very grateful if someone could take the time to explain this to me (step by step would be great)

For a sequence , T=12 and Tⁿ±1 =Tⁿ - 5.
Write down the first four terms of this sequence.

Sorry if I have written this incorrect but the second T is to the power of n+1 (just new to using the symbols above on a PC)

I really could do with some advice on this, I know I'm asking a lot but this is for my sons homework which is due in tomorrow.

Big Thank You To Anyone Who Can Help 

Lea

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Newbie, needing urgent help please

Don't worry, we know what you mean.

You know the first term of the sequence, because you're told that T[sub]1[/sub] = 12.

You can use the second equation to find the next term. For n=1 in that equation, T[sub]2[/sub] = T[sub]1[/sub]-5 = 12-5=7. So T[sub]2[/sub] = 7.

Now that you know the second term, you can use the same method to find the third, which will turn out to be 2. And then the fourth is -3.

That notation is basically just saying to start at 12 and take away 5 for each successive term.

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Why did the vector cross the road?
It wanted to be normal.