All Questions
Tagged with applications algebra-precalculus
44
questions
28
votes
4
answers
6k
views
Consider a man who travelled exactly 2 km in two hours. Is there a one-hour interval when he traveled exactly 1 km?
Question :
Consider a man who travelled exactly 2 km in two hours.
Is there a one-hour interval when he traveled exactly 1 km?
Can we make a mathematical argument?
I have written my attempt in an ...
- 12.3k
3
votes
3
answers
190
views
Real-world examples of the quadratic equation
Does a quadratic equation like $x^2 - ax + y = 0$ describe anything in the real world? (I want to know, if there is something in the same way that $x^2$ is describing a square.)
- 740
2
votes
1
answer
86
views
Extending baker's percentages to preferment recipes
I'm trying to solve a simple problem I created for myself. I'm no mathematician, so any help is greatly appreciated.
Background
In baking and "baker's math", the amount of each ingredient is ...
- 20.6k
6
votes
2
answers
15k
views
What are functions used for?
When I say functions, I don't mean the trigonometric functions like $\sin$, $\cos$, and $\tan$, I mean defined functions like $f(x) = 2x + 4$. Why is $f(x)$ used and why isn't a single variable ...
- 740
0
votes
0
answers
45
views
Where to apply binomial expansion?
I would like to know where I could apply the expression as part of other equation
$$\bigg( 1 + \frac{x}{r} \bigg)^r$$
considering $r \in Z$. It means, in what kind of problem I can use this expression....
- 459
11
votes
3
answers
471
views
Roots of a set of nonlinear equations $ax + yz = b_1; ay + xz = b_2; az + xy = b_3$
Let $a$ be a non-negative real number, $b_1, b_2, b_3$ be real numbers, and $x, y, z$ be variables. Is it possible to analytically find the root closest to origin $(0, 0, 0)$ of the set of nonlinear ...
- 1,545
3
votes
2
answers
1k
views
Real world example of an equation with no solution? [closed]
I have just started reading basic algebra and I have this curiosity that came up when solving basic linear equations. Some equations have no solutions. Are there any real world example of equations ...
- 12.6k
3
votes
2
answers
92
views
Can we find an inverse of a model for deadtime?
This is kind of a real-world question, in that it comes from the work I do, but I'm just pursuing it for my own edification.
When a radiation detector detects an event, it is insensitive to further ...
- 18.7k
1
vote
1
answer
46
views
What method should I use to solve rational equations like this for a different quantity?
With electronics, various characteristics of a device can often be described by solving one equation for different quantities. The problem that I run into a lot with my textbooks is that I can't ...
- 11.2k
1
vote
1
answer
61
views
Why can we say here that $\Delta x_i=dx$ as $i$ approaches infinity?
In the proof of the arc length formula we assume that an element of the arc length is $$\Delta L_i=\sqrt{(\Delta x_i)^2+(\Delta y_i)^2}=\sqrt{1+\left(\frac{\Delta y_i}{\Delta x_i}\right)^2}\space \...
- 1,135
43
votes
18
answers
65k
views
What is an example of real application of cubic equations?
I didn't yet encounter to a case that need to be solved by cubic equations (degree three) !
May you give me some information about the branches of science or criterion deal with such nature ?
- 43.7k
0
votes
0
answers
70
views
Arc length vs Surface of revolution.
I don't understand why these two problems are solved differently here the first one $fig(1)$ and 2nd one $fig(2)$. Why did we take the limit $\displaystyle \lim_{r\to0^+}\int_r^\pi \sqrt{2-2cost}\...
CommunityBot
- 1
0
votes
1
answer
63
views
Why can we apply the surface area of revolution theorem to a spiral?
To find the surface area generated by revolving function f which is smooth on the interval [a,b] and $f(y) \ge0$ around the y-axis we can use the formula $$S=\int_a^b 2\pi rdl =\int_a^b 2\pi f(y)\...
1
vote
1
answer
50
views
Calculus application question
My attempt:
Step 1: Find $x$ in terms of $t$.
$\frac{dt}{dx} = \frac{1}{-0.15x}$
$t = \frac{1}{-0.15}\ln(x) = x^{-1}(t)$
$x(t) = e^{-0.15t}+c$
However, here is where I am stuck. Without any extra ...
- 1,513
73
votes
17
answers
174k
views
What is a real world application of polynomial factoring?
The wife and I are sitting here on a Saturday night doing some algebra homework. We're factoring polynomials and had the same thought at the same time: when will we use this?
I feel a bit silly ...
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