- Fri May 20, 2016 5:27 pm
- Forum: Intermediate Algebra
- Topic: Work problem
- Replies:
**1** - Views:
**46**

How would I do the following work word problem? they show how here: http://www.purplemath.com/modules/workprob.htm Tom and Sam can finish a plowing job in two hours. Tom working alone can do the job in 7 hours. How long would it take Sam to finish the same job alone? do like they show: hours to com...

- Sat May 07, 2016 1:20 pm
- Forum: Matrix (Linear) Algebra
- Topic: find rotation matrix in n dimention
- Replies:
**2** - Views:
**63**

are you asking about what they talk about here? https://en.wikipedia.org/wiki/Rotation_matrix#Geometry

- Sat May 07, 2016 1:15 pm
- Forum: Trigonometry
- Topic: Trig Identity prob: show that cot^2x sinx/(1-sinx)(1+sinx) = 1/sinx
- Replies:
**1** - Views:
**42**

show that cot^2x sinx/(1-sinx)(1+sinx) = 1/sinx i'm taking your eqn to mean this: . . . . . \dfrac{\cot^2(x)\, \sin(x)}{(1\, -\, \sin(x))\, (1\, +\, \sin(x))}\, =\, \dfrac{1}{\sin(x)} use the way they show here: http://www.purplemath.com/modul...

- Sat May 07, 2016 1:01 pm
- Forum: Geometry
- Topic: Challenge: Finding the midline of an irregular shape
- Replies:
**1** - Views:
**62**

your links lead to something that asks for payment or installation of software.

i'm not doing either.

sorry.

i'm not doing either.

sorry.

- Wed Mar 30, 2016 5:11 pm
- Forum: Calculus
- Topic: Equation of a tangent line, did I do this wrong?
- Replies:
**1** - Views:
**138**

(a) By using the definition of the derivative, find y' if y = 6 - 2x - x 2 . (b) Find the equation of the tangent line to the curve at the point (1, 3). (c) Find the point(s) at which the tangent line is horizontal. Here is... my work: (a) -2 - 2x how did...

- Wed Mar 30, 2016 5:05 pm
- Forum: Beginning Algebra
- Topic: Need help with this problem
- Replies:
**1** - Views:
**173**

The Amazon website plans to purchase ads in a local newspaper advertising their site. Their operating budget will allow them to spend at most $2200 on this advertising adventure. They plan to run at most 20 ads. An ad will cost $50 to appear in the weekday paper and $200 to appear in a weekend edit...

- Mon Jan 04, 2016 12:37 am
- Forum: Calculus
- Topic: One more question: line tangent to y=2 sin(2 x+(3pi/4)) at x=pi/8
- Replies:
**4** - Views:
**841**

Wow this is really quick but I have one more question from the book. It's 18 under the AB Diagnostic Test: an equation to the line tangent to y=2 sin(2 x+(3pi/4)) at x=pi/8 is.... the answer is y+ pi/2 = 4x, and I'm struggling with how to get it what did you do after you did the deriv? plz show eve...

- Mon Jan 04, 2016 12:36 am
- Forum: Calculus
- Topic: Help on study question: evaluate lim x->0 (sin^2(4x))/x^2
- Replies:
**1** - Views:
**414**

They kinda explain it, but I don't quite understand how to do the problem how did they do it? where did it not make sense? evaluate lim x->0 (sin^2(4x))/x^2 prob you need to use this lim: \displaystyle \lim_{\theta\, \rightarrow\, 0}\, \dfrac{\sin\left(\theta\right)}{\theta}\, =\, 0 put thi...

- Mon Jan 04, 2016 12:29 am
- Forum: Beginning Algebra
- Topic: Help factoring in the simplest form
- Replies:
**1** - Views:
**782**

..."express in simplest form": ((3((x+1)^(1/2))-5((x+1)^(-1/2)))/(x+1) its kind of hard to read this for sure is it like this? \dfrac{3\, \sqrt{ x\, +\, 1\,}\, -\, \dfrac{5}{\sqrt{ x\, +\, 1\,}}}{x\, +\, 1} i dont know how your book means "simplest" for this prob start w/ common...

- Sat Nov 28, 2015 2:50 pm
- Forum: Trigonometry
- Topic: Trigonometric functions of "theta"
- Replies:
**1** - Views:
**597**

Find the trigonometric functions of "theta". The terminal side of "theta" passes through the given point. (42, -12) My issue is I have the answers which are represented as 7, 2, and, the square root of 53 but I am uncertain as to how one would reach these numbers. ur supposed to...