Solve f(x)=sin(x/2): Find Roots, POI, Min, Max

[d_leet]

end behavior is a straight line going to negative and positive infinity?

What are you talking about? What does the graph of the function y = sin(x) look like?

 

[frenkie]

its an even graph going up to 1 and down to -1...

 

[HallsofIvy]

No, it's not. Since your idea of solving math problems appears to be punching calculator keys, more or less at random, how about graphing sin(x) on a calculator and looking at it?

 

[arildno]

As a follow-up to Halls' suggestion, let Xmin=-20, Xmax=20, Ymin=-1, Ymax=1 (on the Window menu).

What does the graph tell you?

 

[frenkie]

it tells you that the roots of sin(x/2) are at -2Pi, o and 2Pi? this is HARD!

 

[d_leet]

it tells you that the roots of sin(x/2) are at -2Pi, o and 2Pi? this is HARD!

Yes... But there are a lot more zeros than that... What do you know about the sine function?

 

[frenkie]

well its an even function...limits at negative and positive infinity...root at zero? what do u mean when u say there are a lot more zeros?

 

[d_leet]

well its an even function...limits at negative and positive infinity...root at zero? what do u mean when u say there are a lot more zeros?

How can you be asking these questions when you are supposed to be finding the extrema of this function? Surely you must be in a calculus class, and in my experience most calculus classes require some prerequisite knowledge of trigonometry and trigonometric functions. You do realize that the sine funtion is a trigonometric fundtion right?

Next, What does it mean mathematically for a function to be even? Because f(x) = sin(x) is absolutely not an even function.

If a function is even it satisfies the following equlity.
f(x) = f(-x)
graphically this means that the function is symmetric about the y axis.

I have no clue what you mean by "limits at positive and negative infinity" because you give no context for them in the post I have quoted.

And when I say there are a lot more than three zeros, I specifically mean that there are an infinite number of zeros for the function y = sin(x/2) just as there are of the function y = sin(x). If you do not know this you are in no position to be speaking of the limits as x goes to positive or negative infinity, or finding the local extrema of this function. I suggest that you do a bit of research on the sine function before you make any more attempts at this problem.

 

[frenkie]

can u tell me what is greater then 2Pi on a unit circle? please. that's what i need to know.

 

[d_leet]

can u tell me what is greater then 2Pi on a unit circle? please. that's what i need to know.

What are you talking about?

 

[frenkie]

what is greater then 2Pi on a unit circle? it has nothing to do with this problem, i just need to know.

 

[frenkie]

what is greater then 2Pi on a unit circle? it has nothing to do with this problem i just need to know.

 

[d_leet]

what is greater then 2Pi on a unit circle? it has nothing to do with this problem, i just need to know.

It would really help if you would give some context as to what you are talking about, however I would suppose that 3pi, 4pi, 5pi, 1729pi etc.. would all be greater that 2pi...

 

[HallsofIvy]

You are trying to do Calculus problems when you cannot do basic algebra or even arthmetic. I strongly urge you to go to your teacher. You have far worse problems than we can help you with.