# determining

1. ### Need help with determining a statement with quantifiers is true or false

Hello all, I got this one ∀ x ∈ (−∞, −4), if x^(1/3) > 0 then x = −5 I think since the cube root of a negative number can never be positive, and 'if ... then ...' is basically the same thing as p → q, such statement is vacuously true when p is false. So the statement here should be...
2. ### Determining value of constant to give infinite sum of 2

Determine the value of constant c such that \sum _{ n=2 }^{ \infty }{ { (1+c) }^{ -n } } = 2 Apologies if i'm missing something really obvious but should this be solved simply by observing that the denominator of each term becomes infinitely smaller and thus solving the polynomial?
3. ### Determining cone to spherical triangle intersection

I have a sphere (x+x0)^2 + (y+y0)^2 + (z+z0)^2 = 1 formed of spherical triangles. The initial position of the sphere is not defined. Each triangle is determined by 3 normalized vectors (literally spherical triangle is part of a sphere bounded by three planes coming out of the sphere center)...
4. ### Determining if the series converges or diverges

I used the quotient rule to find if the series diverges or converges. I found that It converges. Just to make sure I plugged it in wolfram, wolfram says it diverges. Which one do you think is right?
5. ### Quick question about determining if a sequence diverges or converges

Here they first used l'Hopital's Rule and then used the sandwich theorem. Could we stop with the l'Hopitals Rule and evaluate the limit as n approaches infinity, which would equal to 0. The same answer you would get if you use the sandwich theorem but it's more work.
6. ### Determining the limit of a series.

I've tried to insert everything that is given into the expression but that way i have series with product of series in every denominator, which makes it even more complicated. Any ideas?
7. ### determining if a series is convergent

Given the following series \frac{1}{3} +(\frac{1}{3})^2 + (\frac{1}{3})^3...... to determine if series is divergent using the formula for summing a finite series with a=r=\frac{1}{3} formula =\frac{a(1-r^n)}{1-r} solution given is \frac{1}{3} \frac{(1-1/3^n)}{1-1/3} = \frac{1}{2}...
8. ### Determining Type of Equation

2x+y/x-3y=4 I am to determine if this equation is linear, quadratic, cubic, etc...so I multiplied by the denominator x-3y and got (2x+y)(x-3y)=4(x-3y). This I then multiplied into 2x^2-5xy-3y^2=4x-12y. The book says this is a linear equation, but I was thinking that since it is of degree 2, it...
9. ### Determining Degree of Unknowns in Polynomial

x^2(y + z) = 3 or x^2y+x^2z=3 : x; x and z; x, y, and z; I got the polynomial as being of degree 2 in x, 3 in x and z, and 4 in x, y, and z. However, the book says x, y, and z are degree 3. My question is how is this so, or is the book wrong? I am adding together the 2 from x^2 and each 1 from...
10. ### Determining depth of percentage of sunlight beneath ocean surface

I cannot figure out how to determine at what depth beneath the surface of the ocean that there is 1% sunlight. Here is the function: f(x) = 17(0.965)^x I keep getting 16.405 but am told that is incorrect.
11. ### Determining the price

Tickets for a concert cost $10 each if you order them online, but you must pay a service charge of$8 per order. The tickets are \$12 each if you buy them at the door on the night of the concert. How many tickets can you buy for the same price? How much would they cost?
12. ### Determining graphs

Dominick graphs the equation y=a|x| where a is a positive integer. If Gina multiplies a by -3, the new graph will become 1) narrower and open downward 2) narrower and open upward 3) wider and open downward 4) wider and open upward
13. ### Linear Algebra: Matrices and determining values within matrix

My professor uploaded a document of problems to study for the coming midterm, they do not have solutions so i'm unable to tell if i'm approaching the right result or correct answer, so i'm a bit unsure of this one ( see attachments): " Problem 4: Consider a 2x2 matrix A such that, A =...
14. ### Linear Algebra: Matrices and determining values within matrix

My professor uploaded a document of problems to study for the coming midterm, they do not have solutions so i'm unable to tell if i'm approaching the right result or correct answer, so i'm a bit unsure of this one ( see attachments): " Problem 4: Consider a 2x2 matrix A such that, A =...
15. ### Determining the zero vector

Hello, I have been able to solve part a) of the problem, but I get stuck on b). Can someone give me a hint please, do we need to use the definition of scalar multiplication too to solve for the zero vector?? Thank you for your time.
16. ### Determining if standard dev. is good relative to the mean?

Hi guys, I am doing research which consists of determining life expectancys based on salaries of the 50 states. Here's the thing my instructor said there has to be enough variability in the data between each of the 50 states life expectancys For example if most of them are around 76.7 years...
17. ### Determining speeding up/slowing down from a position graph

I am having trouble figuring out where the particle whose position function is given is speeding up or slowing down. So I believe that it is speeding up (in the negative direction) from 2-3, and slowing down from 3-4. But I am not confident that that is right. I am even less sure about the...
18. ### Determining Null and Alternative Hypothesis for directional Hypothesis testing

So I have been reading notes and been doing exercises on the hypothesis testing and now I understand how to implement the systematic steps of the testing. I still don't understand when I have a directional case what my hypotheses should be. I came across the following question Verify a claim...
19. ### Help on Determining Statistical Method

Please help me determine what statistics should we use IV= Dimple Placement/location, 6 kinds of dimple placement EXAMPLE PIC of our questionair: http://oi61.tinypic.com/350tfg4.jpg DV= Level of attraction Our questionaire looks like this the Picture of the guy with diff kinds of dimple...
20. ### Determining Tangent Line Co-ordinates

Hello! We have a lemniscate curve: 2(x^2+y^2)^2 = 25(x^2-y^2) Its derivative is: y' = \frac{x(25-4x^2-4y^2)}{y(4x^2+4y^2+25)} Now we want to find where it has a horizontal tangent and that is at y'=0 So, \left0 = \right\frac{x(25-4x^2-4y^2)}{y(4x^2+2y^2+25} 0= x(25-4x^2-4y^2), y!=0 x^2+y^2 =...