Lv 31,785 points

# mtf

• ### show that the set X of all vectors that are of a specific form is a subspace?

ive no idea what this question means or how to go about it - studying for a test not hwk related as this is from our review sheet (which is ridiculous already imo)

show that the set X of all vectors that are of the form x = (a, b, 2a, 3b, -a) in which a and b are any real numbers is a subspace of R^5 by finding a set of spanning vectors for W?

what does that mean or how do i start this problem?

• ### Java: how to pass data structure from one package to be used in another?

I have two packages, one holds all the classes that deals with extracting and calculating the data that gets inputted, and the other uses classes where the calculated data should be displayed. How do i pass the array list of objects that i have so that they can be used in another package ??

1 AnswerProgramming & Design8 years ago
• ### Need advice for computing classes?

So there are two equivalent courses (in the sense that if you take one, you cannot take the other for further credit) and so we need to choose between the two to fulfill a requirement. The difference is that course A is with a seemingly bad prof, and you need to learn objective-C (but on your own) for developing iPhone apps (the final project). Course B is with a great prof (having had him before) who teaches you how to use java/android and takes you through a series of projects aimed to prepare you for the final project, an android app.

So my question is - which is more valuable to know, objective-C or java (in those settings mentioned above)?

4 AnswersProgramming & Design8 years ago
• ### tangent lines passing through a point?

find the coordinates of the points where two tangent lines pass through (0,-4) and intersect the parabola y = x^2?

im not sure how to go about this - i know y'(x) = 2x, but if x = 0, then y' = 0 and the slope cannot be zero if its to be passing through (0,-4) - any help is much appreciated thanks!

• ### calc: limits at infinity?

how would you evaluate:

lim x-> negative infinity of x^4+x^5? how is it negative infinity?

• ### limit at infinity - not a rational function?

how would one go about solving for the limit?

lim x->infinity sqrt(9x^2+x)-3x

I tried it the PatrickJMT way (https://www.youtube.com/watch?v=mrKg_5CsfX0

&feature=fvwrel) and ended up with 1/12, when the answer is supposed to be 1/6? Not entirely sure if im going about this the right way - Any help is much appreciated!

• ### how to solve this equation?

1+e^(1/x) = 0? solve for x?

i got x = 1/(ln1) = 1/0 but you cant divide by zero and yet the answer is that x is zero? isnt it undefined?

• ### parametric curve derivative question?

x = 1 + ln (t) , y = t^2 + 2 at (1,2) and youre asked to find the tangent line, how are you supposed to find t? if i sub in x and y i get t = 1 and t = 0 respectively. is that how its done? i got the derivative of the curve as 2t^2. I needed to find t, but not sure how. Any help is much appreciated!

• ### how would you simply this equation?

x^4-1?

how would you expand it?

ex. for things like x^3+8, how would you expand it?? is there a general formula?

• ### supposedly simple derivative question?

how do you take the derivative of:

x^(2x)?

• ### limit question without using l'hospitals rule?

how do you guess the value of the following limit without using l'hospitals rule?

lim x->0 (tanx - x)/(x^3)

• ### calculus - limits at infinity?

how do you evaluate the following?

lim x->pi- cot(x) = cosx/sinx = -1/0- = + infinity

&feature=relmfu

but the answer is -ve infinity:

http://www.wolframalpha.com/input/?i=lim+x-%3Epi-+...

do trig functions need to be evaluated differently?

any help is much appreciated, thanks.

• ### limits at infinity and l'hospitals rule?

lim x-> infinity f(x) = (x - ln( x ) )

• ### What do students studying interactive design do?

how are the job opportunities? what do you work with? (ex. types of software) and how are you liking it?

1 AnswerProgramming & Design8 years ago
• ### how to find the critical points of this function?

of f(x) = e^ (2x) + e^ (-x)

i got f'(x) = 2e^(2x) - e^(-x)

but how do i find the critical points with e?

• ### Mean value theorem question?

let f(x) = (x-3)^(-2). Show that there is no value of c in (1,4) such that f(4)-f(1) = f'(c)(4-1). Why does this not contradict the mean value theorem?

Im not entirely sure what theyre asking here - i did the equation and solved for f'(c) and got 1/4. am i then supposed to prove that there is no x (in the interval) such that 1/4=f'(x)? the function is differentiable over the interval, and therefore continuous right?

• ### Finding derivative of a ln(f(x)) function?

How do you find the derivative of y = ln(x+sqrt(1+x^2))?

I keep trying, but my answer is not right.

• ### velocity question involving calc?

particle moves at: f(t) = t^3-12t^2=36t where t is time in seconds and f(t) is in feet,

find the total distance traveled during the first 8 seconds?

• ### logarithmic derivation?

use logarithmic derivation to find the y'(x) of the following:

y(x) = sqrt((x-1)/(x^4+1))

not sure how im supposed to do this using logs?!