Any math buffs here?

[SweetMary]

Are there any math buffs here? If so, I have a few questions for them.

My math skills are terrible and my math comprehension can only go so far. It has been years since I picked up a book and I am stuck trying to help someone.

*In algebra/geometry/trigonometry, why are letters used in place of numbers?
*What is the usage and meaning of the symbols used in advanced maths such as calculus?
*What is algebra/geo/trig used for?
*Other than in science and engineering, is there any use for advanced-level mathematics?

I do need more help than I am asking for and a good friend of mine is coming to help us in a few hours but would not mind a quick crash course now.

Many thanks and God bless you.​

 

[Dan]

1. to represent numerals that are not known (until the equation is applied) so:

In a right angled triangle, the square on the hypoteneuse is equal to the sum of the squares on the other two sides or if the hypoteneuse is called a, and the other two sides b and c, then the formula is a squared = b squared plus c squared. A well known version is the 3,4,5 method because 5 squared = 3 squared plus 4 squared.

2. How many hours have you got for me to cut and paste a textbook that you wouldn't understand?

3. Algebra -to find numbers that you don't know. Geometry - to work out spatial relationships such as how much carpet you would need for an odd shaped room; Trigonometry - to produce maps with accurate heights and distances.

4. Yes. Statistics.

5. No. They just need to pay attention in classes.​

 

[Bubba]

1 + 1 = 2


Does that help :slap:

 

[ShowmeThemoney]

Good luck to you Sweets.

 

[Macho Man]

Call me up, I will be there soon. I know all numbers, no kidding :tongue:

 

[_ _]

Love me some math but I can not add any more to Dan's comments besides saying that it DOES help you to think analytically. Don't get hung up on why you may not get a particular answer, there is so much more to be gained by studying.

GOOD LUCK!!

 

[Melanie]

Good luck Mary. Please do tell the kids what Sentry said.

Many gains on studying.

 

[tboy]

Now what is it all used for? I use it all the time, constantly, almost minute by minute.

I'm a contractor carpenter and here are some examples:
I have to cut a 8' long 2 x 4 into thirds
I have to cut a 4 x 8 sheet of plywood into 8 pieces
I have to make a round table top, made up of pie shaped wedges
I have to find the exact centre of a circle in order to cut in a smaller circle

Here's a perfect example:
I have to build a cabinet exactly 23 7/8" wide to fit between two columns and 32" high
I have to make doors for that cabinet. The doors are made up of 2 rails (sideways pieces) and 2 stiles (vertical pieces). I have to make a filler panel to fit inside those rails and stiles. The rails and stiles are 1 3/4" wide each. I need a 1/8" gap around the cabinet where the doors overlap.

So, the formula is: 23 7/8" - 1/4" (gap 2 x 1/8") = X (aka door overall size)
Stile size b = 23 7/8" - 1/4" gap - (2 x 1 3/4")
Rail size c = 32" - 1/4" gap - (2 x 1 3/4")

Now I'm not even going to START with the size of the raw material that has to be machined down to 1 3/4". I did a kitchen for a customer who didn't like big gaps between the doors, drawers etc so I had to make the gap 3/16" wide, divided by 2 doors therefore each door had to be 3/32" narrower per side, except for the one on the end that didn't butt up against another cabinet....

Oh, almost forgot the filler panel:
Filler panel width d= 23 7/8" - 1/4" gap - (2 x 1 3/4") + (1/4" x 2) for the amount it sits inside the stiles
Filler panel height e = 32" - 1/4" gap - (2 x 1 3/4") + (1/4" x 2) for the amount it sits inside the rails

 

[tboy]

I saw the same skit in an abbott and costello movie.....believe it or not, there are actually people who do math like that! (and they got loans during the sum prime mortgage blitz lol)

 

[tboy]

Speaking of trig, and y'all can use this, no royalties necessary.

To check to see if an area or space is square, or when laying out the sides of a deck, in relation to the house, use the 3 4 5 rule.

One side measure out 3 feet
At a right angle to that side, measure out 4 feet
The diagonal distance between the 3 foot and 4 foot sides must be 5 feet to be 100% square.

This works in multiples as well for large areas.
So 6 foot and 8 foot should equal 10 feet on the diagonal
9 foot and 12 foot should equal 15 and so on.

 

[Lone Wolf]

This should help

https://www.khanacademy.org/