- Mon Jan 18, 2016 6:17 pm
- Forum: Trigonometry
- Topic: Prove Trigonometric Identities
- Replies:
**1** - Views:
**83**

Could you help me to Prove this : SIN + COS = SIN/1-COT + COS/1-TAN It can't be proved as written. Without the args of each of the trig functions we don't even know what they're asking about. Also your RHS means this: \dfrac{\sin()}{1}\, -\, \cot()\, +\, \dfrac{\cos()}{1}\, ...

- Sat Dec 19, 2015 12:03 am
- Forum: Matrix (Linear) Algebra
- Topic: Find basis and dimension of a vector space
- Replies:
**4** - Views:
**203**

R_4\, is the same notation for \,R^4 But you said other things in other places. Like here you say: \mathbb{R}_4(x)\, is the set of polynomials with a degree not larger than 4. You said something similar here . You were kind-of told here that R 4 would be mapped onto poly's if they were only...

- Fri Dec 18, 2015 11:21 pm
- Forum: Trigonometry
- Topic: Please help me with this problem...
- Replies:
**1** - Views:
**107**

2sec x+8=0 here's what i have so far: 2sec x=-8 sec x = -4 cos x = -1/4 x= arccos (-1/4) ---this is where i'm stuck--- i can get the answer in degree mode but i need it/them in radian mode and it's driving me crazy!!! thank you! Doesn't your calculator say how to convert to radian mode? If you lost...

- Sat Dec 12, 2015 5:51 pm
- Forum: Beginning Algebra
- Topic: Need help with factoring (x^2+xy+y^2)(x^2+y^2)(x-y)^2(x+y)
- Replies:
**1** - Views:
**272**

schwarzechild wrote:I am a bit rusty with factoring polynomials. Any help would be appreciated with the following problem.

(x^{2}+xy+y^{2})(x^{2}+y^{2})(x-y)^{2}(x+y)

I don't know what you started with so I can't say if you did it right but what you've shown is fully factored.

- Tue Nov 03, 2015 1:26 pm
- Forum: Uncategorized
- Topic: 7,7,7,7
- Replies:
**4** - Views:
**255**

Wow. I never would have found either of these. Do you play with these a lot? Maybe they've be good exercise for me.

- Tue Nov 03, 2015 12:13 am
- Forum: Intermediate Algebra
- Topic: Writing rational expression in lowest term; help
- Replies:
**3** - Views:
**392**

\dfrac{a^3\, +\, b^3}{a\, +\, b} Answer is supposed to be a^2\, -\, ab\, +\, b^2 Can anyone explain how to solve this? They're expecting you to remember the special-factoring formula for the sum or difference of cubes. You can find those here . If you apply the sum-of-cubes formula to the top, then...

- Wed Oct 07, 2015 4:26 pm
- Forum: Beginning Algebra
- Topic: Discrete-Time Function
- Replies:
**4** - Views:
**524**

I can write x(n) = u(n) - u(n-4), where u(n) is the unit step function. This this right? n = -5: u(-5) - u(-5 - 4) = u(-5) - u(-9) = 0 - 0 = 0 thru: n = -1: u(-1) - u(-1 - 4) = u(-1) - u(-5) = 0 - 0 = 0 These are right, but: n = 0: u(0) - u(0 - 4) = u(0) - u(-4) = 1/2 - 0 = 1/2 n = 1: u(1) - u(1 - ...

- Tue Sep 29, 2015 1:26 pm
- Forum: Uncategorized
- Topic: Question
- Replies:
**4** - Views:
**326**

Alfred wrote:What does this mean: >i

It probably depends on the context. Where did you see this?

- Mon Sep 14, 2015 11:11 am
- Forum: Intermediate Algebra
- Topic: Linear Programming quiz questions
- Replies:
**2** - Views:
**495**

E. What is the maximum number of extreme points of a feasible region with only one constraint excluding the nonnegativity constraint? My solution: I said that the maximum number of extreme points will not exist because if there is no nonnegativity constraint there is no x and y axes. When they say ...

- Thu Aug 06, 2015 3:51 pm
- Forum: Uncategorized
- Topic: making cubes
- Replies:
**7** - Views:
**638**

Added information: If a cube can be obtained by rotating another cube, these two cubes are NOT considered to be different. So the other reply was right about what to assume. Thanks for that. My 27 is wrong. How do you know? What was your reasoning? My reasoning would start by doing one half (or &qu...