# Search:

Type: Posts; User: JeffM

Page 1 of 20 1

1. ## Thread: If 2^x = 10, then how to calculate the value of 'x'?

by JeffM
Replies
36
Views
694

### I was responding to Jomo, who said that we all...

I was responding to Jomo, who said that we all agreed. Well I don't agree, and I do not know quite what your standing is to tell me that I may not express that disagreement.
2. ## Thread: If 2^x = 10, then how to calculate the value of 'x'?

by JeffM
Replies
36
Views
694

### Finitism is a perfectly respectable position in...

Finitism is a perfectly respectable position in mathematics. Prove that it is false.
3. ## Thread: Factorise x^4 - x^2 + 1 fulling by completing the square

by JeffM
Replies
9
Views
273

### Yes, exactly. The issue is what is the problem...

Yes, exactly. The issue is what is the problem that the OP is supposed to solve. It would be odd to pose a problem to factor an expression (rather than an equation) by completing the square.
4. ## Thread: If 2^x = 10, then how to calculate the value of 'x'?

by JeffM
Replies
36
Views
694

### You have not answered my question at all, but...

You have not answered my question at all, but evaded it. Demonstrate to me a right triangle with provably equal sides. I do not want approximations. I do not want measurements that have some degree...
5. ## Thread: If 2^x = 10, then how to calculate the value of 'x'?

by JeffM
Replies
36
Views
694

### But I do not agree that it is an expressible...

But I do not agree that it is an expressible number and thus do not agree that it is truly a number at all.

But I agree that I may be wrong; I have been before. What number does your calculator...
6. ## Thread: Prove that sum of 1/2 n(n+1) and 1/2 (n+1)(n+2) is always a square

by JeffM
Replies
3
Views
173

### Alternatively, start factoring immediately ...

Alternatively, start factoring immediately

\dfrac{1}{2} * n(n + 1) + \dfrac{1}{2} * (n + 1)(n + 2) = \dfrac{1}{2} * (n + 1) * (n + n + 2) \implies \text {WHAT?}
7. ## Thread: Factorise expression HELP: Does 8ax + 40cx + 3a +18c equal (8x + 3)(a + c) ?

by JeffM
Replies
13
Views
334

### Your purpose was to group terms with a common...

Your purpose was to group terms with a common factor, but the name of the rule that you used is the commutative law of addition, meaning

j + k = k + j.

The rule you used in the other two steps...
8. ## Thread: If 2^x = 10, then how to calculate the value of 'x'?

by JeffM
Replies
36
Views
694

### This thread has delved into a number of ideas and...

This thread has delved into a number of ideas and so may be confusing. Let's recapitulate in one place.

First, it is false that the solution to every valid equation can be expressed exactly in...
9. ## Thread: how to calculate the value of 'x', If 16^x = 2?

by JeffM
Replies
12
Views
272

### 16^x = 2 \implies log_2(16^x) = log_2(2) = 1...

16^x = 2 \implies log_2(16^x) = log_2(2) = 1 \implies WHAT?
10. ## Thread: Justify each step with a property, definition or an operation

by JeffM
Replies
10
Views
327

### And just WHY do you think I spend each Wednesday...

And just WHY do you think I spend each Wednesday afternoon helping students from the local high school individually? Or come here every day? Nice try at deflection, Doctor. (By the way, are you a...
11. ## Thread: Justify each step with a property, definition or an operation

by JeffM
Replies
10
Views
327

### And right there is part of the problem. If we see...

And right there is part of the problem. If we see the list, I bet it will not include all that is needed to justify the student's reasoning. The student will be expected to supplement the list with...
12. ## Thread: Justify each step with a property, definition or an operation

by JeffM
Replies
10
Views
327

### I am not sure that it is technically a...

I am not sure that it is technically a fundamental property. It is certainly a theorem derivable from the definition of additive inverse, a convention of notation, and the following two axioms (or...
13. ## Thread: Calculus limits and negative infinity: lim[x->1](x-7)/(x2 + x - 2)

by JeffM
Replies
10
Views
336

### Well obviously I must agree with that. I was just...

Well obviously I must agree with that. I was just focusing on the difference between calculating limits numerically with respect to functions that are everywhere continuous or are discontinuous only...
14. ## Thread: Integral of 1/(2x+1): different methods give different results??

by JeffM
Replies
4
Views
130

### This is a good question. The terminology can...

This is a good question.

The terminology can be confusing. When we say "plus a constant" with respect to an indefinite integral, we really mean "plus some number." What you did, writing down c to...
15. ## Thread: Calculus limits and negative infinity: lim[x->1](x-7)/(x2 + x - 2)

by JeffM
Replies
10
Views
336

### I disagree. If the question were to give a formal...

I disagree. If the question were to give a formal proof, then you must formally prove continuity before you can substitute. There is, however, no obligation to prove everything from first principles...
16. ## Thread: Problem for game "Forum Mafia" w/ 13 players, 10 good guys and 3 bad guys.

by JeffM
Replies
11
Views
379

### Ahh mon ami, what is the fun in that? Moreover,...

Ahh mon ami, what is the fun in that? Moreover, in my youth, back when mastodons roamed the woodlands, some of my more intriguing questions were posed while I could hardly be called sober. And...
17. ## Thread: Problem for game "Forum Mafia" w/ 13 players, 10 good guys and 3 bad guys.

by JeffM
Replies
11
Views
379

### To avoid testy answers, try comprehensible...

To avoid testy answers, try comprehensible questions. If your question can be asked in a single sentence, give that approach a try.
18. ## Thread: Derivative of derivative? if dx/dy = (g - k)/(k*(y-g)^2)...

by JeffM
Replies
2
Views
90

### Why is this posted in algebra when it seems to be...

Why is this posted in algebra when it seems to be a question in multivariate calculus?

Although it makes no mathematical difference, it is usual to make y the dependent variable when using x and...

by JeffM
Replies
5
Views
168

### If y is bigger than x by 1/8th of x, then y =...

If y is bigger than x by 1/8th of x, then

y = x + \dfrac{1}{8} * x \equiv \left (1 + \dfrac{1}{8} \right ) * x \equiv \dfrac{9x}{8}.

Just different ways to get the same arithmetic result....
20. ## Thread: Quartic Polynomial Factorisation: 5-i is root of 2z^3+az^2+62z+(a-5)

by JeffM
Replies
4
Views
216

### Why are you worrying about problem 7 when you...

Why are you worrying about problem 7 when you have not completed problem 4.

You were to find the both the other zeroes of P(z) and the value of a, given that:

5 - i \text { is a zero of } P(z)...
21. ## Thread: How to calculate the value of X? [X (X-1) (X+2)]

by JeffM
Replies
7
Views
197

### x = 0 \implies x = 0. x - 1 = 0 \implies x =...

x = 0 \implies x = 0.

x - 1 = 0 \implies x = 1.

x + 2 = 0 \implies x = -\ 2.

That certainly does NOT mean that plus 1 and minus 2 are the same number. What it means is that the equation has...
22. ## Thread: How to calculate the value of X? [X (X-1) (X+2)]

by JeffM
Replies
7
Views
197

### There is a basic property of numbers known as the...

There is a basic property of numbers known as the zero product property.

If a product equals zero, then AT LEAST one of the factors must equal zero.

So if x(x - 1)(x + 2) = 0 \implies WHAT?
...
23. ## Thread: Discrete Math: E_1 is scores odd, different; E_2 is scores sum to 8; independent?

by JeffM
Replies
4
Views
178

### Your attempted solution does not seem to be even...

Your attempted solution does not seem to be even addressing the problem given. They give you a helpful clue by suggesting that you think about dice of different colors.

How many any of the 36...
24. ## Thread: Enough conditions for this question? smallest number if exactly 93.6% answered

by JeffM
Replies
8
Views
397

### Yes. Well done.

Yes. Well done.
25. ## Thread: Cross-Price Elasticity of Demand: Which figures to use? (\$50/gallon of crude oil)

by JeffM
Replies
2
Views
157

### For reasons known only to themselves, economists...

For reasons known only to themselves, economists use mathematical conventions different from those used by mathematicians and physical scientists. Moreover, economists use "elasticity" in two...
Results 1 to 25 of 500
Page 1 of 20 1