Some Trig Questions (EXAM TOMORROW)

[JCoupe]

I have a mid-term exam for FST(Func, Stats, Trig) tomorrow. I lost my notebook, and I have a few questions.

1) How do you find a linear model on a calculator? If you can't how do you find it on paper?

2) What are the equations for Exponential Growth & Decay? If there are none, how do you tell the difference?

3) The population of Cedar Ridge was about 3300 in 1996 and was increasing at a rate of 2.1% annually.

A) Write an equation that gives the population of Cedar Ridge p, n years after 1996.

P=3300 (1.021)^n .

My Question: how come there's a 1 in front of the decimal when 2.1% = .021?

I don't really understand Translations/Transformations. Does anyone know of a good site that'll help me learn them?

-Thanks, any help is greatly appreciated.

 

[Denis]

P=3300 (1.021)^n .
My Question: how come there's a 1 in front of the decimal when 2.1% = .021?

The 1 represents $1 (or a unit) so that (1 + i)^n gives the future value of 1;
then this can be multiplied by any amount to give the corresponding future
value of that amount; like, if 1 apple costs 25 cents, then 20 cost 5 bucks.

 

[Gene]

1) What kind of calculator?

2) Most equations have e^x or n^x in them. If x is positive it is growing. Otherwise it is decaying.

3) If it grows 2% (.02) you still have what grew. You could say if 100 grows 2% it grows 2 so now you have 2 + 100 = 102 or 100 + 2 or 100*1+100*.02 but that equals 100*(1+.02) so you say 100*(1.02). Thats where the 1 comes from.

Today is a little late to start.

 

[JCoupe]

i found out #1, #2, #3. I had an old test on translations / transformations and she let us use it and it had tons of work on it, i think i did good on the exam.

 

[Gene]

Yippie!!!
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Gene