Math's Q7 Kinda confused

fontdor

OK So paper 1 q.7 Edco Sample A asks write the period and range. I got the period as 4 and range as -2,2

then it says find f(101) and the solution says f(101-100) = f(1)=0

now where the heck did that 100 come out of?

Leaving Cert Student

fontdor wrote: »

OK So paper 1 q.7 Edco Sample A asks write the period and range. I got the period as 4 and range as -2,2

then it says find f(101) and the solution says f(101-100) = f(1)=0

now where the heck did that 100 come out of?

the period should be in terms of pie I would have thought? usually pie or two pie.. hang on I'll have a look!

Leaving Cert Student

Leaving Cert Student wrote: »

the period should be in terms of pie I would have thought? usually pie or two pie.. hang on I'll have a look!

I have the edco papers but my sample A doesn't have this question?! what page is it in yours?

fontdor

Leaving Cert Student wrote: »

I have the edco papers but my sample A doesn't have this question?! what page is it in yours?

it is on page 48

Leaving Cert Student

fontdor wrote: »

it is on page 48

This isn't in my papers... you sure they are this year's edco?

fontdor

Leaving Cert Student wrote: »

This isn't in my papers... you sure they are this year's edco?

yes it's blue in color and says at the side ''includes new SEC project Maths Sample Papers 2013'' then at the bottom it says Includes 19 exam papers.

Leaving Cert Student

fontdor wrote: »

yes it's blue in color and says at the side ''includes new SEC project Maths Sample Papers 2013'' then at the bottom it says Includes 19 exam papers.

oh this is ordinary level?

fontdor

Leaving Cert Student wrote: »

oh this is ordinary level?

Yes it is ordinary level

Moody_mona

An easy way to do that f(101) is to do repeated subtraction of the period from whatever the number is, so 101-4-4-4-4-4 etc until the number is on your graph and you can answer the question based on it. This example they just did it quicker and they said 101-25(4), so the number take away 25 periods.

Leaving Cert Student

Ok you should have mentioned the level dude!

Moody_mona

Leaving Cert Student wrote: »

the period should be in terms of pie I would have thought? usually pie or two pie.. hang on I'll have a look!

The period does not need to be in terms of pi, even at higher level, completely depends on the function.

fontdor

Leaving Cert Student wrote: »

Ok you should have mentioned the level dude!

Agreed my bad soz dude and thanks for the help

Leaving Cert Student

Moody_mona wrote: »

The period does not need to be in terms of pi, even at higher level, completely depends on the function.

Oh right it usually is though! As in radians

Moody_mona

Absolutely, because it's normally a trigonometric graph asked, but it doesn't have to be

LostBoy101

When you see something like that always take the f number (i.e. 101) repeatly away from the period (i.e. 4) until the last positive number.

Moody_mona

LostBoy101 wrote: »

When you see something like that always take the f number (i.e. 101) repeatly away from the period (i.e. 4) until the last positive number.

Other way around, take the period away from the "f number" and it doesn't have to be the last positive number, it just has to be a number that's on your graph so you can answer it.

Leaving Cert Student

Moody_mona wrote: »

Other way around, take the period away from the "f number" and it doesn't have to be the last positive number, it just has to be a number that's on your graph so you can answer it.

youre hardly in pass?

Moody_mona

I'm a teacher.

LostBoy101

Moody_mona wrote: »

Other way around, take the period away from the "f number" and it doesn't have to be the last positive number, it just has to be a number that's on your graph so you can answer it.

Ah I see, thanks!