## Search found 358 matches

Tue Jan 03, 2017 9:33 pm
Forum: Trigonometry
Topic: Equivalent expressions Trig: sin theta + cos theta ( sin theta/cos theta)
Replies: 3
Views: 728

### Re: Equivalent expressions Trig: sin theta + cos theta ( sin theta/cos theta)

The little mistake you made is that cot is cos/sin and not sin/cos. The final answer is csc. Just FYI: Sine, cosine, tangent, etc, are functions, so they need arguments. Just as you wouldn't say "ln", because natural log needs to be the log of something, so also you can't say "sin" and "cos" withou...
Thu Dec 01, 2016 12:12 pm
Forum: Forum Rules & Guides
Topic: Hello, I'm Rose
Replies: 3
Views: 1654

### Re: Hello, I'm Shao

Uh, I don't really get how this site is organized.
The forums are organized by area of study, starting from very early "Arithmetic", progressing through pre-algebra and algebra levels, and up past calculus and differential equations. Pick the area that matches what you're studying right now.
Fri Nov 04, 2016 3:45 pm
Forum: Calculus
Topic: Chain Rule - Do not understand step by step
Replies: 1
Views: 1457

### Re: Chain Rule - Do not understand step by step

Reading a book I got stuck in this (uploaded an image under the following link) http://img1.imagilive.com/1116/aww-board.png x(t) = A*cosine(wt+Phi) The first derivative is: dx/dt = -Aw*sin(wt+Phi) I know that this result is right, for the first derivative, i just dont know how to get there, (step ...
Fri Sep 30, 2016 10:59 pm
Forum: Geometry
Topic: Two parallel lines cut by a curved line
Replies: 7
Views: 884

### Re: Two parallel lines cut by a curved line

I drew dotted imaginary lines connecting L4 and L1 as well as L3 and L2, then used supplementary angle theorem to determine the missing angles by subtracting what were given by 180 and worked my way to x being 38. But that was not the answer. Okay; I'll need to see your work in order to check it. B...
Tue Sep 27, 2016 10:53 pm
Forum: Geometry
Topic: Two parallel lines cut by a curved line
Replies: 7
Views: 884

### Re: Two parallel lines cut by a curved line

How do you find x? It's not 38. Could it be 37? What is the use of the 75 angle? Okay; I'm going to guess that the exercise was actually something like this: Given that lines L1 and L2 are parallel, that lines L3 and L4 meet at point "p" between lines L1 and L2, that the acute angle formed by lines...
Mon Sep 05, 2016 3:09 pm
Forum: Beginning Algebra
Topic: Simplifying is not working for me: (3/2)(4x - 7) + (3x - 2)/4
Replies: 1
Views: 524

### Re: Simplifying is not working for me: (3/2)(4x - 7) + (3x - 2)/4

I am trying to simply this following equation: . . . \dfrac{3}{2}\, (4x\, -\, 7)\, +\, \dfrac{3x\, -\, 2}{4} Can someone let me know how to solve this? You say that you're needing to "solve this" "equation", but there is no "equals" sign in what you've posted. Is maybe the "plus" sign a typo for th...
Thu Aug 11, 2016 5:26 pm
Forum: Forum Rules & Guides
Topic: Hello, I'm Rose
Replies: 3
Views: 1654

### Re: Hello, I'm Rose

I'm going into 10th grade this year, at age 18 and really need help in math. Hello!
Welcome! Please review this forum's rules and how to type math clearly. Then pick an appropriate category, and post your question. Thank you!
Mon Jul 18, 2016 9:29 pm
Topic: (log x)^3= log x^3
Replies: 4
Views: 7305

### Re: (log x)^3= log x^3

How do I see how to solve this? I do not see where to get the information. Try studying the lessons at the links the other poster gave you: Do a log rule to get the power on the right outside of the log. http://www.purplemath.com/modules/logrules.htm 1. This first step explains that you need to app...
Sat May 14, 2016 10:56 pm
Forum: Trigonometry
Topic: Averaging Amplitudes of Different Frequency Bands
Replies: 1
Views: 613

### Re: Averaging Amplitudes of Different Frequency Bands

Hello everyone! I am in a pickle right now as I attempt to move forward in my research project on neurofeedback. I am trying to calculate the theta/beta ratio for individual subjects and then compare them statistically. Are you talking about brain waves, like they show here ? The issue I am having ...
Sat May 14, 2016 10:43 pm
Forum: Calculus
Topic: How to prove f(x) = (cx-c*x+x-1)/(2x-x-1), where 1<c<2 is decreasing function?
Replies: 3
Views: 806

### Re: How to prove f(x) = (cx-c*x+x-1)/(2x-x-1), where 1<c<2 is decreasing function?

I have plotted the aforementioned function curves of f(x) with different c, and found that it seems to be monotony function. However, it is too hard to me to prove it. May you help me ?
How did they do the proofs in their worked examples? What method are you expected to use? Thank you!