Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [problem-solving]

Use this tag when you want to determine the thinking that is needed to solve a certain type of problem, as opposed to looking for a specific answer to a question.

Use this tag when you want to determine the thinking that is needed to solve a certain type of problem, as opposed to looking for a specific answer to a question.

4495 questions
0
votes
0 answers

Compounding Formula (and its reverse)

I've written a program in which I'm using a compounding calculator to determine an output. But without a formula I'm having trouble reversing the calculation. Given a compounding problem whose variables are: i: initial amount (eg: 2000), d: divisor…
aarondl
  • 1
0
votes
1 answer

Concavity intervals

My second derivative is $$\frac{(250-64 x^3)}{(3 x (-125+8 x^3))^\frac{5}{3}} $$ I know that function is undefined if $x = 0$ and $x=5/2$. What would be concavity intervals? Why not $(-\infty,0)$,$(0,5/2)$ - Increasing and $(5/2,\infty)$ -…
Sergey Tsibel
  • 125
0
votes
2 answers

Solve for X and Y

I have the following equation: $0 = 34x^2+92xy+68y^2−250x−344y+461$ I cannot find any way to get the values of both x and y from this equation, any help would be much appreciated, especially a step by step solution. Edit: I'm quite new to this site,…
Rlz
  • 227
0
votes
1 answer

Trying to re-write the formula for the present value of an annuity to solve for annuity value

I have the formula: $$PV = C * {{(1-(1+r)^{-n})} \over r}$$ This is the formula for the Present Value (PV) of an Annuity (C) with interest (r) (for example 5% interest is 0.05) over (n) periods. I would like to rewrite the formula so that I can…
Duci
  • 3
0
votes
1 answer

Survey Results Computation Problem Solving

I encountered this kind of question in an employment exam. I am just curious how to compute this. I already forgot the actual numbers so I will change them to variables. There is a survey for a product for A number of people regarding its quality…
Spade
  • 3
  • 1
0
votes
1 answer

Dropping a box from a quadcopter

I am trying to estimate when and where to release a box carried by a delivery UAV such that it falls on a given target. I need to take the wind speed/direction into account. (See the visual below for reference.) Through the pose estimator, I have…
csg
  • 233
0
votes
0 answers

How to keep the rod in equilibrium?

What would be the force F to keep the rod AB in equilibrium? I got confused while using Lami's theorem. $$\frac{F}{\sin160^\circ}=\frac{F_1}{\sin60^\circ}=\frac{W}{\sin140^\circ}$$ If F is keeping it in equilibrium, I can also write,…
raf
  • 155
0
votes
2 answers

Basic "Punctuation" and "words" used in basic Mathematics

I live in a place where solving math problems is taught perfectly, but Punctuation and correct words are overlooked. I don't know to use comma, period, dash, paragraph change, etc and words like assuming, therefore, since, etc. Please help me by…
Kumar sadhu
  • 111
  • 2
0
votes
0 answers

How to form an equation based off $x$ and $f(x)$ values

So I'm making a program (and I know, this isn't stack overflow) but I need help on ONE algorithm in order to finish it for good. Here's the pattern I'm dealing with: When $x = 8, f(x) = 1$ When $x = 10, f(x) = 4$ When $x = 13, f(x) = 8$ This is…
CurlyFry
  • 79
0
votes
1 answer

Help to understand on atcoder Math problem statement

I stumble on this question (https://atcoder.jp/contests/abc116/tasks/abc116_c) and I cannot for my life understand what the problem ask me to solve So I understand these part: we have N flowers each flowers start at 0 heights we have sequences of…
sswastioyono18
  • 1
0
votes
1 answer

NP-hard problems of feasibility

What does "deciding if a system X of equations has a solution is NP-hard" really mean? Is it equivalent to say that finding a solution to this system is NP-hard? If we can solve, we can decide. But what about the converse? Thank you
Adam54
  • 301
0
votes
2 answers

How would you define a superproblem?

Assuming that we have a problem, how would one classify its superproblem? There could be multiple ways to generalize a problem and for example two superproblems (although including the original as a subproblem) may not be compatible. I am not sure…
user
  • 67
0
votes
1 answer

Equation/Algebra

Ethan, Mcdonald and Willie earns $\$51700$ a month. Ethan earns $\$400$ less than Mcdonald and Willie earns $\$3000$ more than Ethan. How much do they all earn each? Mcdonald's earnings is $X$. Ethan: $x - \$400$ Willie: $x - \$400 + 3000$ I…
Mumini Erhan
  • 1
0
votes
1 answer

You see a row of 5 trees, each one 20 meters from the next. How long is the row?

I'm thinking of this problem in 2 ways. There's 5 trees, each the same width $X$. This leaves 4 inner "gaps" of $20$ meters in length? So, my answer would be $(20 \times 4) + (5\times X)$ or rather $80 + 5x$ If there's 2 trees, from each end…
Ludwigthestud
  • 195
1 2 3
…
28 29