Math question, brainiacs!

[Sashac]

y = 2sin(4x) - 5

Find the vertical shift and the horizontal and vertical compression/expansion from the original equation:

y = sin(x)

This is worth 10, 000 bonus marks.. which pretty much means I don't have to do the rest of the course haha. It might be impossible cause I don't know why he's offering so much bonus.

Anyways, have a shot at it if you like..

 

[skier_bum]

as far as i can tell the vertical shift is 5 down, and the compression is a multiplied by 2. I plugged it into my graphic calculator and thats wat it showed. Thats sounds too easy tho

 

[Sashac]

Yeah, def too easy.. cause if you make a table of values for y = sin(x) and times the y coordinates by 2 and then add 5 it doesn't match up with the y coordinates for the manipulated equation..

I actually figured out that the number 7.99 seems to work nicely as the vertical expansion buuut I can't seem to get taht number out of the equation..

if taht makes sense?

 

[skier_bum]

well im looking at the calculator, and this is wat its showing me.

y1 = 2sin(4x)-5

y2 = sin(x)

x y1 y2

0 -5 0

1 -4.86 0.01745

2 -4.72 0.0349

3 -4.584 0.05234

 

[nickmcnutt]

are you in math 12?

because it has nothing to do with calculations at all. the answers are in the equation.

 

[Sashac]

Haha, we're stupid...

Vertical shift: -5

Horizontal compression: 1/4

Vertical expansion: 2

I was doing the right thing but I had my calc in degrees so the answers never worked out right! Haha, oh well at least I got it eventually

I hope this means I get 10 000 bonus marks cause that would bring me up to.. hm, I dunno, 1000%..

siiiiick

 

[freezed]

i was about to post that exact thing. DARN!

I was sure it would get me e-cool points!

 

[Sashac]

yeah, math 12

weve had like 3 classes tho and havent started yet.. just review so far.. but he gave us this question for fun i guess? ive never seen a sin graph before haha

 

[nickmcnutt]

welcome to 5 months of number HELL

math 12 sucks, but just think... no more math after january, ever, besides baisic addition/subtraction.

 

[Sashac]

haha i'd like to think that.. too bad i'm goin to college and will probably end up takin it again

 

[nickmcnutt]

ahh, shitty. well just know that the question you just asked is pretty much the easiest question in math 12. enjoy!

 

[St.Steezy]

I'm doing the exact same stuff right now in math.

 

[mad_540_trix]

haha yeah i wish i could go back to that stuff, now i'm in university and i'm doing calculus (which isn't that hard anyways, but still).

 

[freezed]

you think math 12 sucks, wait till calc in college!

 

[Mr_Bojangles]

haha the answer was in the equation all along, gotta love circular functions.