Need help graphing trig functions!! please (2 Viewers)

[FcUk]

Hey guys i was doing the 2001 past hsc and a few questions had to graph harder functions... the books go over the basics but they never tell you how to do the harder ones im referring especially to Q10 iii) but can someone give me a link or a brief overview of the general rules when graphing the HARDER trig functions

Cheers

 

[somborac]

i dont know weather this will be any help

but always find the equation i.e. y = whatever

from there derive it and find maximums and minimums and point inflextion

and then sub 0 into equation y = whatever to find the why intercepts

 

[alex tonkin]

look mate i could... but wat the fucks in it for me. nah just kidding, but seriously. I dont even know wat a fukin curve is mate so ur already far beyond me... good luck to ya.

 

[FcUk]

lol thaks for the confidence boost ill be thinking of ya when i do my exam

somborac i dont mean curve sketching i mean stuff life sin(2x)+3 stuff liek that... also i dont get how you convert the numbers on a number line to a number in terms of pie... like i know how to convert radians and stuff but in the 2002 hsc Q8)b)ii) they ask for when the particle is at rest, the numbers on the number line are not in terms of pie yet the answers are all in terms of pie and i know how they go em?

 

[smallcattle]

Go download Graphmatica, I find it very usefull when checking the graphs

 

[Seraph]

if you are really in doubt use a table of values

but what exactly is the problem

e.g in a curve such as y = 2sin 3x

we know our amplitude is 2 , if its the period you are worryign about we can find that using
2pi/n
however
if you remember your standard Trig graph then all you need to do is this

3x = pi/2
3x = pi
3x = 3pi/2
3x = 2pi

and so forth.......

also if it has a + 3 or something then obviously its not starting at the origin so you have to put 0 into the equation to see where your y intercept is ...

but yea trig graphs are like messy -_-

 

[FcUk]

if you are really in doubt use a table of values

but what exactly is the problem

e.g in a curve such as y = 2sin 3x

we know our amplitude is 2 , if its the period you are worryign about we can find that using
2pi/n
however
if you remember your standard Trig graph then all you need to do is this

3x = pi/2
3x = pi
3x = 3pi/2
3x = 2pi

and so forth.......

also if it has a + 3 or something then obviously its not starting at the origin so you have to put 0 into the equation to see where your y intercept is ...

but yea trig graphs are like messy -_-

haha life saver all i was need was how to find the x-intercepts thanks mate

 

[Xayma]

Also if asked to graph something such as
y=cos x+ sin x.

You will probably be asked to graph both y=cos x, y=sin x and add ordinates.

If not quickly and lightly sketch in pencil y=cos x, y=sin x.

After that find the values for all important points, 0, π/4, π/2, 3π/4, π etc.

And draw the shape of the graph off that.