Maths help: sin and cosine
 

Well I got my Math-Finals tomorrow and have just been doing some exercises. But I'm stuck on this part. Maybe someone does understand it on here

When I got this calculation:
http://i.imgur.com/sNOtl.png

I don't get the part inside the [] brackets
I know that they made it something like
x-3/4 = sin(φ)
but how did they mix it with the cos²(φ) to -((x-3)/4)²+1 ?


Would be cool if someone could help me

2+2=4
ez

isnt it sine and cosine?
anyway do you know SOH CAH TOA?

Random post?

oh jea <.<

Just the names but never used it. Also it's most likely not related to what I need

You've basicly solved it already, you just have to put the sine in the equation.

i hate math with a passion and got in fights with serveral horrible math teachers over the years, so i cant really help.

Well just looked into another solution and there it said almost the same


sin(φ) = (x-3)/4

y = 4+8*(1-sin²(φ))

sooo is cos²(φ) the same as 1-sin²(φ)?

Yupp.
I kind of suck at explaining stuff so i'll just give you a link to wikipedia

http://en.wikipedia.org/wiki/Pythago...etric_identity

Sorry :(

Ah thanks a lot! You saved my day :)

OPPOSITE OVER HYPOTENUSE IS SINE i win gibe me cookie

Is this pre-cal? o.o

What are you talking about?

Precalculus*

Gues so. Never heard of Precalculus but from what I found in Google it seems to be something like that

Man I was always horrible at math.

Triangles :(

Not related, soh cah toa is used for geometric purposes and this isn't for finding the measure of an angle or segment of a triangle.

This question is damn hard too, I'm supposedly at genius level at math and I can't even solve it QQ.