Facebook Page
Twitter
RSS
Tab Content
  • MarkFL's Avatar
    Yesterday, 22:32
    MarkFL replied to a thread Radius of Circle in Pre-Calculus
    That is the radius of the circle after it has been increased by $a$ units. If I tell you that my weight increased by 20 lbs., then you know my...
    4 replies | 48 view(s)
  • MarkFL's Avatar
    Yesterday, 21:35
    MarkFL replied to a thread Radius of Circle in Pre-Calculus
    Let's let $0<a$ be the number units the radius must be increased. And so the change in area we can write as: \Delta A=\pi(r+a)^2-\pi r^2=b Now...
    4 replies | 48 view(s)
  • topsquark's Avatar
    Yesterday, 20:41
    Looks good. -Dan
    2 replies | 29 view(s)
  • I like Serena's Avatar
    Yesterday, 12:05
    I like Serena replied to a thread ideal gas in Other Topics
    Hi markosheehan, Yes, there are Van der Waals forces in all cases. However, Helium is the only one that is electrically neutral. That's because...
    1 replies | 45 view(s)
  • I like Serena's Avatar
    Yesterday, 11:52
    I like Serena replied to a thread copper(2) oxide in Other Topics
    Yes, there are exceptions. Most elements have a stable bonding with a full outer shell, but they typically also have alternative stable bondings....
    5 replies | 74 view(s)
  • I like Serena's Avatar
    Yesterday, 09:08
    I like Serena replied to a thread copper(2) oxide in Other Topics
    Hi markosheehan, I'm assuming EC stands for Electron Configuration? Before the bonding Copper has the configuration 2-8-18-1 (there are 18...
    5 replies | 74 view(s)
  • Joppy's Avatar
    Yesterday, 07:16
    Joppy replied to a thread copper(2) oxide in Other Topics
    The abbreviation EC has quite a few meanings in chemistry, can you be more clear about it please. Anyway, copper (II) is a bit of an exception...
    5 replies | 74 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 21:53
    MarkFL replied to a thread The Distance Across in Geometry
    \overline{MK}=\sqrt{(\sqrt{2}a)^2+(\sqrt{2}b)^2}=\sqrt{2\left(a^2+b^2\right)}=\sqrt{2(50)}=\sqrt{100}=10 :D
    8 replies | 83 view(s)
  • topsquark's Avatar
    March 25th, 2017, 21:31
    At a guess you are forgetting about the cross term. (a + b)^2 \neq a^2 + b^2. It is (a + b)^2 = a^2 + 2ab + b^2. You are going to end up having to...
    4 replies | 56 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 21:07
    MarkFL replied to a thread Lagrange Multipliers 2 in Calculus
    I arbitrarily chose another point on the constraint, so that we could do a comparison like I mentioned just now in the other thread. :D
    9 replies | 82 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 21:04
    MarkFL replied to a thread Lagrange Multipliers in Calculus
    I chose the point as it is on the constraint. Using that point, we can determine if our one critical point is a maximum or a minimum. If the...
    9 replies | 70 view(s)
  • greg1313's Avatar
    March 25th, 2017, 20:52
    Rewrite as $\sqrt{2t+5}+\sqrt{2t+8}=\sqrt{8t+25}$. What do you get when you square both sides?
    4 replies | 56 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 19:21
    MarkFL replied to a thread Lagrange Multipliers 2 in Calculus
    I agree that the point $(2,2)$, is the only one that meets all criteria. Now we need to compare the value of $f$ at another point on the constraint,...
    9 replies | 82 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 19:08
    MarkFL replied to a thread Lagrange Multipliers in Calculus
    I agree that of the 3 critical points, $(1,1)$ is the only one in quadrant I. Now, we know this is either a maximum or a minimum, and to determine...
    9 replies | 70 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 11:15
    MarkFL replied to a thread Factoring...6 in Pre-Calculus
    It might be more clear to state something like the following: The difference of cubes formula states: p^3-q^3=(p-q)\left(p^2+pq+q^2\right) ...
    5 replies | 73 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 10:47
    MarkFL replied to a thread Lagrange Multipliers 2 in Calculus
    Consider: e^u=0 What do you get when solving for $u$? Okay, you correctly found $x^2=y^2$...what do you get when you substitute for...
    9 replies | 82 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 10:39
    MarkFL replied to a thread Lagrange Multipliers in Calculus
    What I would do is use the constraint to determine $y=2-x$. Now substitute for $y$ in both equations you mentioned, and solve for $x$, then your...
    9 replies | 70 view(s)
  • I like Serena's Avatar
    March 25th, 2017, 06:59
    Hey evinda!! (Smile) I haven't figured it out yet. :( However, I can see a couple of approaches... According to Euler we have: $$a^{\phi(pq)}...
    1 replies | 57 view(s)
  • MarkFL's Avatar
    March 25th, 2017, 02:30
    This is a calculus question...please don't continue to post calculus questions in other forums. If given: ...
    3 replies | 84 view(s)
  • greg1313's Avatar
    March 24th, 2017, 23:17
    greg1313 replied to a thread Factoring...8 in Pre-Calculus
    1. Correct. 2. Correct. 3. Yes, apply the sum of cubes formula to $8a^3+27b^3$. Be careful with your variable names. $a$ does not necessarily...
    2 replies | 39 view(s)
  • topsquark's Avatar
    March 24th, 2017, 23:16
    topsquark replied to a thread Factoring...7 in Pre-Calculus
    I mentioned this in another thread. Don't set the LHS of "a = a + b" It's too confusing. -Dan
    3 replies | 48 view(s)
  • topsquark's Avatar
    March 24th, 2017, 23:13
    topsquark replied to a thread Factoring...6 in Pre-Calculus
    You need to clarify your variables. "b = (a - b)" isn't right. Pick a variable name, say, p... Anything but that b on the LHS.... Then you have p...
    5 replies | 73 view(s)
  • MarkFL's Avatar
    March 24th, 2017, 23:12
    MarkFL replied to a thread Lagrange Multipliers 2 in Calculus
    If you solve both equations for $\lambda$ and then equate the results, you obtain: \frac{ye^{xy}}{2x}=\frac{xe^{xy}}{2y} Multiply through by 2:...
    9 replies | 82 view(s)
  • greg1313's Avatar
    March 24th, 2017, 22:57
    greg1313 replied to a thread Factoring...7 in Pre-Calculus
    $$(a-b)^3=a^3-3a^2b+3ab^2-b^3$$ Rearrange: $$\begin{align*}a^3-b^3&=(a-b)^3+3a^2b-3ab^2 \\ &=(a-b)^3+3ab(a-b) \\ &=(a-b) \\...
    3 replies | 48 view(s)
  • MarkFL's Avatar
    March 24th, 2017, 21:24
    MarkFL replied to a thread Lagrange Multipliers in Calculus
    Okay, so what this implies is: \frac{x}{\sqrt{6-x^2-y^2}}=\frac{y}{\sqrt{6-x^2-y^2}} Cross-multiply: x\sqrt{6-x^2-y^2}=y\sqrt{6-x^2-y^2} ...
    9 replies | 70 view(s)
  • topsquark's Avatar
    March 24th, 2017, 21:05
    topsquark replied to a thread Factoring...5 in Pre-Calculus
    Yeppers! -Dan
    2 replies | 33 view(s)
  • I like Serena's Avatar
    March 24th, 2017, 17:47
    Actually, f(n)=2n is not a bijection, since for instance 1 does not have an original. But it does free up all the odd rooms, so that a new arrival...
    1 replies | 45 view(s)
  • MarkFL's Avatar
    March 24th, 2017, 16:18
    MarkFL replied to a thread The Distance Across in Geometry
    Using the Pythagorean theorem, we find: \overline{MK}=\sqrt{(\sqrt{2}a)^2+(\sqrt{2}b)^2}=\sqrt{2\left(a^2+b^2\right)} Now, we know that...
    8 replies | 83 view(s)
  • greg1313's Avatar
    March 24th, 2017, 13:33
    Is the angle contained by $a$ and $b$ equal to $90^\circ$? For that matter, what is the complete problem?
    2 replies | 67 view(s)
  • MarkFL's Avatar
    March 24th, 2017, 06:10
    MarkFL replied to a thread [SOLVED] Minimum of function under constraint in Calculus
    I would use W|A: W|A - optimize 2x+y subject to xy=18
    8 replies | 254 view(s)
More Activity

2 Visitor Messages

  1. Reply/View Conversation
    Hi, pls help me to solve for x, 2^x =8x. Thanks.
  2. Reply/View Conversation
    Hello and welcome to MHB, mathlearn!

    If you have any questions or comments about the forums, please feel free to address them to me or another staff member. We are happy to help and look forward to your participation here!

    On Behalf Of MHB's Staff,

    Ackbach.
Showing Visitor Messages 1 to 2 of 2
About mathlearn

Basic Information

Signature


Thousands of candles can be lighted from a single candle, and the life of the candle will not be shortened. Happiness never decreases by being shared.

Statistics


Total Posts
Total Posts
341
Posts Per Day
1.39
Thanks Data
Thanks Given
460
Thanks Received
168
Visitor Messages
Total Messages
2
Most Recent Message
February 8th, 2017 17:48
General Information
Last Activity
March 17th, 2017 10:37
Last Visit
March 16th, 2017 at 02:30
Last Post
March 16th, 2017 at 02:15
Join Date
July 24th, 2016

7 Friends

  1. caffeinemachine Offline

    MHB Journeyman

    caffeinemachine
  2. greg1313 Offline

    Perseverance

    greg1313
  3. I like Serena Offline

    MHB Seeker

    I like Serena
  4. Joppy Offline

    MHB Apprentice

    Joppy
  5. MarkFL Offline

    Pessimist Singularitarian

    MarkFL
  6. topsquark Offline

    MHB Journeyman

    topsquark
  7. ZaidAlyafey Offline

    زيد اليافعي

    ZaidAlyafey
Showing Friends 1 to 7 of 7

March 16th, 2017


March 10th, 2017


Ranks Showcase - 1 Ranks
Icon Image Description



Name: MHB Model User Award (2016)
Issue time: January 9th, 2017 14:39
Issue reason:
Math Help Boards