Need Help understanding explanation.

Problem: https://brilliant.org/practice/stunt-driving-and-collisions/?p=4

I do not understand how they were able to arrive to the solution. The explanation is confusing me. Is anyone able to help me understand this? Thank you.

#Algebra

Note by Dacota Sprague
1 year, 12 months ago

No vote yet
1 vote

  Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

  • Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
  • Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
  • Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
  • Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold

- bulleted
- list
  • bulleted
  • list

1. numbered
2. list
  1. numbered
  2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1

paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
    # 4 spaces, and now they show
    # up as a code block.

    print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in \( ... \) or \[ ... \] to ensure proper formatting.
2 \times 3 2×3 2 \times 3
2^{34} 234 2^{34}
a_{i-1} ai−1 a_{i-1}
\frac{2}{3} 23 \frac{2}{3}
\sqrt{2} 2 \sqrt{2}
\sum_{i=1}^3 ∑i=13 \sum_{i=1}^3
\sin \theta sin⁡θ \sin \theta
\boxed{123} 123 \boxed{123}

Comments

OK. The faster train has the velocity of v1=100 v_{1} = 100 and slower one v2=−50 v_{2} = -50 (mind the direction!) Now, this is the system of equations you need {v1t=d1v2t=d2d1+∣d2∣=D \begin{cases} v_{1}t = d_{1} \\ v_{2}t = d_{2} \\ d_{1} + \left| d_{2} \right| = D \end{cases}

I hope this helps.

Tomasz Bukowy - 1 year, 12 months ago

So I have to ask. How does this result in x106? Also, thank you. This is starting to make a little more sense.

Dacota Sprague - 1 year, 12 months ago

Honestly, I have no clue where they got this weird notation from. Idk what x106 or x108 means there either, but D6 \frac{D}{6} is the correct answer for certain.

Tomasz Bukowy - 1 year, 12 months ago

That might have been what they were going for, but they may have made a mistake in the formatting. Thank you for the help!

Dacota Sprague - 1 year, 12 months ago

Yeah. Np.

Tomasz Bukowy - 1 year, 12 months ago
×

Problem Loading...

Note Loading...

Set Loading...