## View Poll Results: What is the hardest math you learned?

Voters
105. You may not vote on this poll
• Calculus (specify in comments)

38 36.19%
• Trigonometry

11 10.48%
• (Enriched) Geometry

11 10.48%
• Equations (specify)

4 3.81%
• Graphing Equations (specify)

2 1.90%
• Basic Algebra (specify)

7 6.67%
• I can do better!

24 22.86%
• What kind of math is that?!

8 7.62%

# Thread: Calculator/Math Thread

1. I'm bored. Someone give me a random derivative to do please. No weird functions like Li(x), x!, W(x).

2. Originally Posted by ben1996123
I'm bored. Someone give me a random derivative to do please. No weird functions like Li(x), x!, W(x).
x*sinx*e^x*lnx*cosx

3. Originally Posted by Hyrtsi
I love maths. I've been doing research on my own on various problems and theorems, even came up with something on my own.

I'd like to see different ways to solve this:

Proof that

Originally Posted by y235
It's pretty easy.
Spoiler:
$x=1+\frac{1}{1+x} \\ x=\frac{2+x}{1+x} \\ x(1+x)=2+x \\ x^2+x=x+2 \\ x^2=2 \\ x=\sqrt2$
Originally Posted by Sa967St
Spoiler:
I had the same solution as y235 (ninja'd ), but just for lols I'll sub in an x somewhere else.

or

assumed convergence fail?

moral of the story: you can't just "set some infinite thingy equal to x" without first proving that such an x exists

4. how do you get that?

5. Hardest for me was basic algebra. Why? I had the teacher that couldn't teach. I suck at math because of him.

6. 'Extended' product rule:

If with n functions, and where n(x) is the nth function, . It's probably known, but I found it myself today so I thought I'd post it.

Originally Posted by tozies24
Spoiler:
Not using e because

extended product rule

Here's a derivative for someone to do:

Hint:

7. Pretty good example ben its all simple calculus just lots and lots of it. Will post a solution tomorrow, its 2:54 am atm and ive got lectures tomorrow morning, been teaching some friends how to cube

Also someone can try i.e. the area enclosed by and

8. Twenty people are to travel in a bus from the airport to the hotel at the resort. The bus is designed for use in a tropical climate; it can carry twelve passengers outside and eight inside. If four of the passengers refuse to travel outside and five will not travel inside, in how many ways can the passengers be seated if the combinations of passengers inside or outside is not considered except to take into account these wishes?

Answer:
Spoiler:
330

9. How can a branch of math be the "hardest" if everything connects to each other? It's like you have a million puzzles pieces, and just as you learn a new branch of math you manage to put together a hundred pieces.... only to find out a thousand more are missing. What's difficult for someone depends on which puzzle pieces are already assembled.
Spoiler:
sais the man who hasn't even taken calculus yet :P

10. Originally Posted by Sahid Velji
Twenty people are to travel in a bus from the airport to the hotel at the resort. The bus is designed for use in a tropical climate; it can carry twelve passengers outside and eight inside. If four of the passengers refuse to travel outside and five will not travel inside, in how many ways can the passengers be seated if the combinations of passengers inside or outside is not considered except to take into account these wishes?

Answer:
Spoiler:
330
The answer seems low, and it's not even close to what I thought it was.
How did you arrive at that?

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