View Profile: MarkFL - Math Help Boards

Today, 02:28

MarkFL replied to a thread Quadratic Inequality...6 in Pre-Calculus

'Factor: (x^2-9)(x^2-16)\le0 Continue factoring...:D

1 replies | 10 view(s)

Today, 02:25

MarkFL replied to a thread Quadratic Inequality...5 in Pre-Calculus

You want to determine the roots of both the numerator and denominator as your critical numbers (i.e., values for which the expression can change...

1 replies | 11 view(s)

Today, 02:02

MarkFL replied to a thread Inequality & Calculator in Pre-Calculus

Move everything to the LHS, and then combine all terms into a rational expression...what do you then have?

1 replies | 15 view(s)

Yesterday, 22:03

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

We require both: 0<x 0<12-x Combined, this gives us: 0<x<12

18 replies | 132 view(s)

Yesterday, 21:41

MarkFL replied to a thread Stanley A. Ellisen...Quotes in Chat Room

For better forum organization, I have merged the 4 threads pertaining to Stanley A. Ellisen quotes into one thread. This way they can all be...

4 replies | 42 view(s)

Yesterday, 21:12

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

x and x - 12 represent lengths (assumed to be in cm)...and so must be positive. Lengths cannot be negative, and if we are to actually have two pieces...

18 replies | 132 view(s)

Yesterday, 19:13

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

At this point you can multiply through by 8 to get: x^2-12x+32>0 Then factor: (x-4)(x-8)>0 Now solve this inequality, subject to:

18 replies | 132 view(s)

Yesterday, 11:04

MarkFL replied to a thread Find Perimeter of Rectangle in Pre-Calculus

When I was a student, I found one of the best ways to understand things is to look at them in general terms. For example, in this problem, rather...

21 replies | 179 view(s)

Yesterday, 10:49

MarkFL replied to a thread Find Perimeter of Rectangle in Pre-Calculus

What we see is that we must have: L=W And so, what we have found is that for a rectangle of a given area, the perimeter is the smallest it can...

21 replies | 179 view(s)

Yesterday, 10:34

MarkFL replied to a thread Find Perimeter of Rectangle in Pre-Calculus

Your next step should be: (L-W)^2=0 So, how must L and W be related in order for this to be true?

21 replies | 179 view(s)

Yesterday, 10:28

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

No, what we want is: A\left(W_1\right)+A\left(W_2\right)>5 A(x)+A(12-x)>5 Now, the arguments for the area function represent wire lengths,...

18 replies | 132 view(s)

Yesterday, 10:10

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

Yes, now we need to answer the question: For which values of x will the combined areas of the squares exceed 5 cm^2? We have two pieces of wire...

18 replies | 132 view(s)

Yesterday, 10:00

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

Okay, you have a piece of wire whose length is let's say W...you bend it into a square...what is the perimeter of the square? Then using your formula...

18 replies | 132 view(s)

Yesterday, 09:55

MarkFL replied to a thread Find Perimeter of Rectangle in Pre-Calculus

Yes, once you simplify, you will find the implication. :D

21 replies | 179 view(s)

Yesterday, 09:53

MarkFL replied to a thread Quadratic Inequality...4 in Pre-Calculus

Yes, now combine terms on the LHS...:D

5 replies | 48 view(s)

Yesterday, 09:44

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

Let's use x for the length of the sides of the square, so we have: P=4x A=x^2 Now, we want to replace x in the formula for the area with an...

18 replies | 132 view(s)

Yesterday, 09:39

MarkFL replied to a thread Find Perimeter of Rectangle in Pre-Calculus

You're just seeing what the equation implies about the relationship between L and W. :D

21 replies | 179 view(s)

June 23rd, 2017, 22:50

MarkFL replied to a thread Find Perimeter of Rectangle in Pre-Calculus

We have: \sqrt{LW}\le\frac{L+W}{2} When I ask "when does equality occur," I am essentially asking you to solve: \sqrt{LW}=\frac{L+W}{2} ...

21 replies | 179 view(s)

June 23rd, 2017, 21:56

MarkFL replied to a thread 206.07.05.88 partial fractions??? in Calculus

I would look at a substitution like: u=\sqrt{x^2+4x+3}\implies dx=\frac{u}{x+2}\,du And the integral then becomes: I=\int\frac{1}{u^2+1}\,du

1 replies | 27 view(s)

June 23rd, 2017, 19:33

MarkFL replied to a thread Two Pieces of Wire in Pre-Calculus

What is the area $A$ of a square whose perimeter is $P$?

18 replies | 132 view(s)

June 23rd, 2017, 19:25

MarkFL replied to a thread Quadratic Inequality...4 in Pre-Calculus

You don't want to multiply an inequality by an expression whose sign is unknown...arrange everything to one side and then get your critical values...

5 replies | 48 view(s)

June 23rd, 2017, 19:21

MarkFL replied to a thread Quadratic Inequality...3 in Pre-Calculus

You are assuming x is positive when you do that. A better step is to subtract x/2 from both sides: \frac{2}{x}-\frac{x}{2}<0 Combine terms: ...

2 replies | 37 view(s)

June 23rd, 2017, 15:00

MarkFL replied to a thread Quadratic Inequality in Pre-Calculus

Yes, we have a parabola opening upwards, and given that it has two real roots, we should expect to find it to be negative in between its roots. :D

7 replies | 73 view(s)

June 23rd, 2017, 14:44

MarkFL replied to a thread I have mathematics problems for solving but i can not understand how to solve these mathematics? in Pre-Calculus

Okay, I have several issues here: 1.) We ask that you post no more than 2 questions per thread: 2.) You've shown no effort:

1 replies | 66 view(s)

June 23rd, 2017, 13:38

MarkFL replied to a thread Quadratic Inequality...2 in Pre-Calculus

In this problem, you have a function representing a parabola that opens upwards. We should then expect, given that it has two real roots, that the...

7 replies | 77 view(s)

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June 24th, 2017

Math Help Boards

We are an online community that gives free mathematics help any time of the day about any problem, no matter what the level. You will have to register before you can post. To start viewing messages, select the forum that you want to visit from the selection below.

MarkFL Pessimist Singularitarian MHB AdministratorMHB CoderMHB Math HelperMHB Ambassador

Mini Statistics

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Visitor Messages

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June 24th, 2017

MarkFL

Pessimist Singularitarian

MHB Administrator
MHB Coder
MHB Math Helper
MHB Ambassador