Tab Content
• Today, 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,...
6 replies | 47 view(s)
• Today, 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...
6 replies | 40 view(s)
• Today, 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) ...
4 replies | 56 view(s)
• Today, 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...
6 replies | 47 view(s)
• Today, 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...
6 replies | 40 view(s)
• Today, 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 | 51 view(s)
• Today, 02:30
This is a calculus question...please don't continue to post calculus questions in other forums. If given: ...
3 replies | 78 view(s)
• Yesterday, 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 | 38 view(s)
• Yesterday, 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...
4 replies | 56 view(s)
• Yesterday, 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:...
6 replies | 47 view(s)
• Yesterday, 22:18
Yes. Then in case of doubt you after factoring can multiply and see the result
4 replies | 56 view(s)
• Yesterday, 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} ...
6 replies | 40 view(s)
• Yesterday, 21:05
topsquark replied to a thread Factoring...5 in Pre-Calculus
Yeppers! -Dan
2 replies | 27 view(s)
• Yesterday, 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 | 40 view(s)
• Yesterday, 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...
6 replies | 63 view(s)
• Yesterday, 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 | 249 view(s)
• Yesterday, 04:29
The objective function is linear, so it describes a plane, and so I don't believe there will be any saddle points, or in fact any critical points...
4 replies | 60 view(s)
• Yesterday, 04:04
MarkFL replied to a thread Boat direction in Calculus
Is this a calculus-based physics course?
6 replies | 91 view(s)
• Yesterday, 01:37
What I would do is observe that we have cyclical symmetry, that is we may interchange $x_1$ and $x_2$ with no change in either the objective function...
4 replies | 60 view(s)
• Yesterday, 01:25
MarkFL replied to a thread The Distance Across in Geometry
Not quite...it would be \sqrt{2}a and \sqrt{2}b...so what would the diagonal of the rectangle be?
6 replies | 63 view(s)
• March 23rd, 2017, 21:17
MarkFL replied to a thread The Distance Across in Geometry
I would let $a$ be the length (in cm) of the segments with 1 tick mark, and $b$ be the length (in cm) of the segments with 2 tick marks. And so,...
6 replies | 63 view(s)
• March 23rd, 2017, 19:30
MarkFL replied to a thread Boat direction in Calculus
Being that it is an optimization problem, on a function in two variables, the way I worked it using the calculus is the most straightforward way I...
6 replies | 91 view(s)
• March 23rd, 2017, 12:53
MarkFL replied to a thread Boat direction in Calculus
I think what I would do is orient a coordinate system such that south is up and west is to the right. At time $t=0$, have boat A at the origin, and...
6 replies | 91 view(s)
• March 23rd, 2017, 11:28
There are online calculators that will spit out the answer to this question, however if you want genuine help, we need to know what you've tried, or...
3 replies | 102 view(s)
• March 23rd, 2017, 07:08
subtraction 20% is same as finding 80% of the same or multiplying by .80 deviding by 1.2 is not same as \finding 80% you get 100/1.2 = 83.3 % ...
2 replies | 49 view(s)
• March 23rd, 2017, 06:49
we are here to help you and not solve your problem, kindly inform what you have tried so that we can guide you .
3 replies | 102 view(s)
• March 23rd, 2017, 03:19
MarkFL replied to a thread Factoring...3 in Pre-Calculus
Finding what to multiply together to get an expression. It is like "splitting" an expression into a multiplication of simpler expressions.
6 replies | 74 view(s)
• March 23rd, 2017, 02:50
MarkFL replied to a thread Factoring...3 in Pre-Calculus
I would say division is the inverse of multiplication, but factoring is certainly related to division. For example, we know: ...
6 replies | 74 view(s)
More Activity

### 24 Visitor Messages

1. Happy Birthday Opalg!! So glad you're here for another year. Have a great time celebrating.
2. Hi Opalg, happy birthday! How are things?
3. Happy birthday!
4. Hello Opalg, I am unable to post a reply to your response due some bugs in the website on the thread I started regarding complexification. I have asked Jameson to look into the issue. I will reply as soon as the issue is resolved.
5. HB, Opalg!
6. I actually was just going to send you a Happy Birthday wish...I hope you have a good one and I hope you enjoy your time in Gran Canaria too!
7. Happy Birthday, Opalg! I hope you are in good company and in good spirits today.
8. Happy Birthday, Sir!
9. Happy Birthday, Prof. Opalg!! Your sharp mind and kind manner are truly an asset to MHB! I hope you have a great day and all your wishes come true!
10. Many happy returns of the day, professor Lance!

...Oh wait, I like Opalg better!
Showing Visitor Messages 1 to 10 of 24
Page 1 of 3 123 Last
Page 1 of 3 123 Last

#### Basic Information

Date of Birth
January 17
Location:
Leeds, UK
Occupation:
Retired maths professor
Country Flag:
Great Britain

#### Signature

Was sich überhaupt sagen lässt, lässt sich klar sagen; und wovon man nicht reden kann, darüber muss man schweigen.

(Anything that can be said at all, can be said clearly; and whereof one cannot speak, thereon one must be silent.)

– Ludwig Wittgenstein's good advice for forum contributors, in Tractatus Logico-Philosophicus.

#### Statistics

Total Posts
2,052
Posts Per Day
1.10
Thanks Given
693
5,836
2.844
##### Visitor Messages
Total Messages
24
Most Recent Message
January 17th, 2017 21:13
##### General Information
Last Activity
March 23rd, 2017 04:44
Last Visit
March 22nd, 2017 at 17:14
Last Post
March 20th, 2017 at 16:23
Join Date
February 7th, 2012
http://www.thelances.co.uk

### 24 Friends

1. #### AlexmahoneOffline

MHB Craftsman

2. #### anemoneOffline

Paris la ville de l'amour

3. #### Chris L T521Offline

MHB Journeyman

4. #### cooliceey002Offline

MHB Apprentice

5. #### cupofcoffeeOffline

MHB Apprentice

6. #### DreamWeaverOffline

MHB Craftsman

7. #### FantiniOffline

MHB Craftsman

MHB Seeker

9. #### jacobiOffline

MHB Apprentice

10. #### JamesonOffline

Администратор

Showing Friends 1 to 10 of 24
Page 1 of 3 123 Last
Page 1 of 2 12 Last

#### March 21st, 2017

• 10:27 - anemone clicked Thanks for this post: -= Hidden Content =- by Opalg

#### March 7th, 2017

Page 1 of 2 12 Last
Ranks Showcase - 8 Ranks
Icon Image Description

 Issue time: January 9th, 2017 14:43 Issue reason:

Name: MHB Analysis Award (2016)
 Issue time: January 9th, 2017 14:37 Issue reason:

 Issue time: January 7th, 2016 11:12 Issue reason:

Name: Graduate POTW Award (Jul-Dec 2013)
 Issue time: January 5th, 2014 16:52 Issue reason:

Name: MHB Pre-University Math Award (Jul-Dec 2013)
 Issue time: January 5th, 2014 16:47 Issue reason:

Name: Graduate POTW Award (Jan-June 2013)
 Issue time: July 1st, 2013 22:07 Issue reason:

Name: MHB Advanced Algebra Award (Jan-June 2013)
 Issue time: July 1st, 2013 22:03 Issue reason:

Name: MHB Analysis Award (Jan-June 2013)
 Issue time: July 1st, 2013 22:02 Issue reason: