Sign in to follow this  
Followers 0
cassidy

Anybody any good at maths?

22 posts in this topic

Is there any way to tell the difference between a cos graph, and a shifted sin graph that goes through (0,1)?

 

In a test we were given a graph and asked to give the equation. I called it a shifted sin graph, but could it have been either?

Share this post


Link to post
Share on other sites

If it was y=(sin x) + 1, then it's not a cos graph. Or y= -((sin x) -1) Typically, they look the same. If the inflection doesn't reverse around the x axis, then it's definitely a shifted sine wave. I'd have to see the question to be certain though.

Share this post


Link to post
Share on other sites

If it was y=(sin x) + 1, then it's not a cos graph. Or y= -((sin x) -1) Typically, they look the same. If the inflection doesn't reverse around the x axis, then it's definitely a shifted sine wave. I'd have to see the question to be certain though.

 

That sounds right. Or it could be the integral of sin(x)...What level math are you in?

Share this post


Link to post
Share on other sites

If it was y=(sin x) + 1, then it's not a cos graph. Or y= -((sin x) -1) Typically, they look the same. If the inflection doesn't reverse around the x axis, then it's definitely a shifted sine wave. I'd have to see the question to be certain though.

 

That sounds right. Or it could be the integral of sin(x)...What level math are you in?

 

year 11. what's the curriculum like in the US?

 

we do cubics, bit of quadratics, diff and antidiff, logs and expo, unit circle and other trig, and that's about it

Share this post


Link to post
Share on other sites

If it was y=(sin x) + 1, then it's not a cos graph. Or y= -((sin x) -1) Typically, they look the same. If the inflection doesn't reverse around the x axis, then it's definitely a shifted sine wave. I'd have to see the question to be certain though.

 

That sounds right. Or it could be the integral of sin(x)...What level math are you in?

 

year 11. what's the curriculum like in the US?

 

we do cubics, bit of quadratics, diff and antidiff, logs and expo, unit circle and other trig, and that's about it

 

 

Sounds a little like you are doing either Pre Calculus or beginning year Calculus (I did Pre Calc in my senior year of HS, and once again at the college level in my freshman year. Calculus I, I took at the end of my freshman - beginning sophomore year of college. Would have taken it earlier, but chickened out a bit because I intensely disliked geometry in my freshman year of HS. I was terrified that Calc would be just like that course... but it really was not too bad. Still prefer my sciences though).

 

Though that type of question does pop up in Trigonometry or Analytic Geometry (which I took in the 11th grade, and in college they combined them with Calculus classes...so it is like taking two or even three classes at once). Sounds actually almost like you are taking this type of class more than the calc. :blush: For the record, I liked Trig & Analyt Geometry and Calc III better than Calculus I & II

 

Also I agree with youbroughtheryouRiker & Trekkie Mage. it does sound right.

Edited by Yillara_Skye

Share this post


Link to post
Share on other sites

I used to be good at this stuff. Unfortunatly that was like 4 years ago, but I am planning to take a calculus class in the spring which will hopefully have this all come back to me.

Share this post


Link to post
Share on other sites

I used to be good at this stuff. Unfortunatly that was like 4 years ago, but I am planning to take a calculus class in the spring which will hopefully have this all come back to me.

 

is calculus an american form of math>?

Share this post


Link to post
Share on other sites

^It's a kind of advanced math, dealing more with Analytic Geometry and Trig.

Share this post


Link to post
Share on other sites

I used to be good at this stuff. Unfortunatly that was like 4 years ago, but I am planning to take a calculus class in the spring which will hopefully have this all come back to me.

 

is calculus an american form of math>?

 

It was invented by an Englishman.

Share this post


Link to post
Share on other sites

I used to be good at this stuff. Unfortunatly that was like 4 years ago, but I am planning to take a calculus class in the spring which will hopefully have this all come back to me.

 

is calculus an american form of math>?

 

 

Here is a link that has some of the equations and discussions of Calculus

 

Calculus section at MathematicsWorld

Share this post


Link to post
Share on other sites

That looks hard.

Share this post


Link to post
Share on other sites

That looks hard.

 

once you've got your head around it, it's not too bad. how old are you, if i may ask?

 

17 years old. :blush:

Share this post


Link to post
Share on other sites

I'm in BC Calculus for whoever asked...Just took my integrals/derivatives test o.O

 

Calculus is the study of motion in mathmatics. It applies trig and functions with some more complicated stuff. It's really not too difficult so long as you start out with the basic stuff. Plus there are a lot of shortcuts (power rule, chain rule, quotient rule, product rule... :drool: )

 

Year 11? Hrm. And you're dealing with sin/cos...I'd guess it would be the something similar to algebra II/precalc/trig here. What subjects are you covering?

Share this post


Link to post
Share on other sites

As I have seen in one of the prior responces to the question: I would need to see the actual graph to tell. a f(x)=sin x (0,0) Now a cos phased either direction of 1/2 Htz would resemble a sin wave. Sin x/1 would give you a scs. That would be a mirror image of the sine function.

 

As both looke the same {f(x)=sin x ~ f(x)=cos x +- 1/2} in a graph form, either answer would be acceptible unless the instructor has given other boundries to the equation. If all else fails you, do attempt the proof.

Share this post


Link to post
Share on other sites

As I have seen in one of the prior responces to the question: I would need to see the actual graph to tell. a f(x)=sin x (0,0) Now a cos phased either direction of 1/2 Htz would resemble a sin wave. Sin x/1 would give you a scs. That would be a mirror image of the sine function.

 

As both looke the same {f(x)=sin x ~ f(x)=cos x +- 1/2} in a graph form, either answer would be acceptible unless the instructor has given other boundries to the equation. If all else fails you, do attempt the proof.

 

ta muchly! my teacher hasn't given us the test back.

 

i still haven't finished calculus for the year, even though exams are coming up. since we have limited time to cover all the information, my teacher is skimming over it all, which is really bad considering some of the stuff is pretty tricky. like finding the area enclosed by a quadratic/cubic and the x-axis.

Share this post


Link to post
Share on other sites

 

i still haven't finished calculus for the year, even though exams are coming up. since we have limited time to cover all the information, my teacher is skimming over it all, which is really bad considering some of the stuff is pretty tricky.

I know that feeling! :laugh: It is pretty tough for fly over five chapters and you have to have a grasp on the concepts by the finals.

 

We ran out of time and had to do double and triple integrals, introduction to Ordinary Differential Equations, surface area, Taylor and Maclaurin Series, Arc Length, Projections, 2 and 3 D graphing (equations of Ellipsoides, Hyperboloids and such, cylinders with one variable missing)

 

 

Ordinary Diff Equations was not much better, we had a ton to go over and no time to finish. Euler, Improved Euler, Wronksian, Kramers Rule, Laplace Transforms and a few other topics all in maybe five class periods (the class only met once a week for 75 minutes for the semester) - like the Calc I, II & III it was a college class for me

Share this post


Link to post
Share on other sites
Guest
You are commenting as a guest. If you have an account, please sign in.
Reply to this topic...

×   You have pasted content with formatting.   Remove formatting

  Only 75 emoticons maximum are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

Loading...
Sign in to follow this  
Followers 0