# Search results

1. ### Well, I've forgotten intermediate algebra

University used bookstores are great places for this as well. I've actually spent the last 3 months working through a pre-calculus textbook that I only paid \$5 for used. Between that, khanacademy, and other sources it's been fairly painless. I just go through a section one day and do all the...
2. ### Happy Pi day! Down with Pi?

Seems equally easy to remember as with pi to me. That is, if you were a person learning from scratch.
3. ### Happy Pi day! Down with Pi?

I think the point is that the radius is the fundamental unit. Diameter can always be broken down into radius. Plus.. in real life you can't just take a tape measure and hope to find the absolute value of the diameter. This is because you can't be sure you're going through the center of the...

5. ### Happy Pi day! Down with Pi?

Curious on people's thoughts. Especially since most people here are a lot better at math than me! https://www.youtube.com/watch?v=jG7vhMMXagQ
6. ### Trig Need help, thanks! Equation

What is the reference angle for 380 degrees? Think how that relates to the sin of 20 degrees and tan. The value for tan should pop out at you! Edit: Then think about what the reference angle for 200 degrees is.
7. ### Trig Question

Well, first, your picture must be incorrect. A tangent line will touch the circle at a single point only. Are you sure that's all the information you have?
8. ### Help on vocab.

It's the symbol for an intersection in set theory. So, it refers to the elements that are common to both sets. For example, if you had these two sets: {1,2,3,4} {3,4,5,6} The elements common to both sets would be 3 and 4. (Where the two sets intersect).
9. ### What's with the brain controlling head,arm,leg in an upside down way?

It means that if you move your leg, for example, that a particular area of the motor cortex will be active. Of those neurons that are active, a certain number of them will connect to other neurons (or many other neurons) that eventually exit the brain as a nerve bundle of axons that control the...
10. ### Complex Math Logic Problem

Edit: I just noticed this is a take home exam, so I'm only going to give you a vague hint. You know you have three categories, and you know that those categories overlap. Is there anything you learned in class that could visually show 3 overlapping categories?
11. ### Calculators Should i bother getting a graphing calculator?

I have a cheap Texas instruments scientific calculator (under \$15) that can find standard deviation, standard error, sums of squares, and other statistical information. No it can't do linear regression (or any other kind of regression), but I would much rather do those things with software...
12. ### Calculators Should i bother getting a graphing calculator?

Agreed, if you're doing statistics then a full computer with software is far superior. Who wants to spend all day entering data sets?
13. ### Calculators Should i bother getting a graphing calculator?

Just as a tip if you decide you need one, Ebay is actually a good place to get a good deal on a graphing calculator, especially during the summer when people are trying to get rid of them. Graphing calculators don't seem to change a whole lot, so getting a good used one might be a great way to...
14. ### Calculating Averages: Not so simple after all?

What you're doing is actually very interesting because it is very similar to how statistics works. You could think of taking the average of all of the numbers as finding the true average of that population of numbers. Taking the average of all small subsets is similar to statistical sampling...
15. ### Biology research - do ppl have to argue for how relevant+interesting it is?

A lot of it does have to do with who's willing to give you money to do the research. Hence why medical-related research is focused on so much. A granting agency is also going to be more willing to fund you for an established model organism. Not to mention facilities/procedures are already...
16. ### Can neocortex initiate emotional behaviour and what is it?

Taking part in a process is different than determining that process. The moral values of a culture are not determined by the biology of the Brain. Of course the Brain has a part to play in social interaction and development. In understanding the rules, having a theory of mind, and all those...
17. ### Can neocortex initiate emotional behaviour and what is it?

Sure, there's connections between both systems. You can activate an emotional response just by having a certain idea. It's not like the limbic system is isolated from the rest of the brain. Humans are not unique in this regard, and it has nothing to do with moral values. Moral values are...
18. ### Simple dipstick problem

I found this on wikipedia... which might help http://en.wikipedia.org/wiki/Circular_segment" [Broken] You need to rewrite the area formula in terms of the height of the liquid, and I think that R = h + (r-h) gives you a way to do that.
19. ### Simple dipstick problem

I thought I would mention another thing. If you take the area of the "pie slice" that is marked by the lines drawn to the top of the chord (including the area that is swept out to the bottom of the tank), and then you subtract the area of the triangles above the liquid, that should give you...
20. ### Simple dipstick problem

Well, I can say this much. If you look at the cylindrical tank from one of the ends, you would have a circle with the liquid coming up a certain height of the circle. Therefore the problem becomes a question of finding the area of the segment of the circle below the chord marked by the top of...
21. ### Simple dipstick problem

You know what, I think I actually made a mistake. I think you're actually going to have to use some trigonometry to solve this. I'll have to think about this a bit.
22. ### Simple dipstick problem

In that case you need to rewrite the volume equation for the cylinder in terms of the diameter of the cylinder. Remember that radius = 1/2 the diameter. That way you'll know the volume that corresponds to the "diameter height" that you have written on the dipstick. Is the cone attached to the...
23. ### Simple dipstick problem

Well, you could start by focusing on the cylinder. If the volume of the cylinder is volume = pi * radius^2 * height Can you rewrite the equation so that you solve for height? If you can do that you know that a certain height on the dipstick will correspond to a certain volume of the...
24. ### Can i kill milk bacteria in a microwave

I think there's something else you might want to consider. The reason why you simmer the milk, on the stove, as opposed to letting it boil, is because the milk might curdle if you boil it too long. This is because of the Casein protein in mammalian milk. Since the microwave is going to be...
25. ### What is brain plasticity?

Usually when you're talking about neuroplasticity, you're talking about the ability of certain brain areas to take over functions of the brain that have been damaged. As an extreme example, you can actually remove an entire hemisphere of the brain in early life, and the remaining hemisphere...

I just though I would mention something you might want to try. If you take ax^2+ bx+ c= 0 and factor it the way that HallsofIvy says, you'll actually end up with the quadratic formula. Just in case you wanted to see where the quadratic formula comes from. Edit: This video might help you...
27. ### Lactose intolerance

It's perfectly logical, Native Americans are a migration of Asians and therefore share many traits with them.
28. ### Teachin of Evolution in Schools

Do you learn that apples fall to Earth because of gravity OR MAYBE little forest spirits want to return their spiritual energy to Mana at the center of the Earth. Or maybe an invisible Sasquatch tied invisible ropes to all the apples in the world and pulled them towards his lair at the center...
29. ### Teachin of Evolution in Schools

Evolution isn't a choice, it's how biology works. You learn how math works in school, how gravity works, how chemistry works, and you most definitely should learn evolution so you know how biology works. And to make an informed decision you need to know the evidence. Going home, sitting on...
30. ### Teachin of Evolution in Schools

I gave up trying to convince people like this long ago. If someone wants to ignore a plethora of converging evidence and basic logic, well then fine. But when it comes to teaching about a topic, like biology, you damn well better teach what the evidence is for that topic and not random...