## Search found 23 matches

Wed Jul 29, 2009 7:25 pm
Forum: Trigonometry
Topic: if x=1/2 and (x+1)(y+1)=2, find rad. meas of arctanx+arctany
Replies: 4
Views: 3318

### Re: if x=1/2 and (x+1)(y+1)=2, find rad. meas of arctanx+arctany

Perhaps you should start by determining the value of y.
Thu Jul 23, 2009 8:18 pm
Forum: Pre-Algebra
Topic: Mixed Numbers with Variables
Replies: 2
Views: 2971

### Re: Mixed Numbers with Variables

As a college math teacher, I would read $a\frac{2}{3}$ as a students mistake in representing $\frac{2}{3}a$ which would be interpreted as 2/3 TIMES a (i.e. 2/3 is the coefficient on a).

I've never seen variables used in mixed numbers.
Thu Jul 23, 2009 8:15 pm
Forum: Intermediate Algebra
Topic: height above trampoline modelled by h = -4.9(t - 1)^2 + 6.3
Replies: 3
Views: 3994

### Re: height above trampoline modelled by h = -4.9(t - 1)^2 + 6.3

Ok...This particular quadratic is written in the form y = a(x-b)^2+c which is just a transformation of the basic y = x^2 quadratic which has a vertex at (0, 0). The two most important transformations for your question are the value of b and c. The b value tells you how far to the right the vertex ha...
Thu Jul 23, 2009 4:46 am
Forum: Intermediate Algebra
Topic: height above trampoline modelled by h = -4.9(t - 1)^2 + 6.3
Replies: 3
Views: 3994

### Re: height above trampoline modelled by h = -4.9(t - 1)^2 + 6.3

This type of function is called a quadratic whose graph is a parabola. The highest(lowest) point of a parabola is called the vertex. Do you know how to find the vertex of a parabola?
Thu Jul 23, 2009 4:41 am
Replies: 1
Views: 1623

I don't see any radicals. What I see is:

$\mbox{Example: }\underline{K}+\underline{2K} = \underline{-5}\\6\,3\,2$

If you don't know how to insert equations, could you use sqrt(stuff) to indicate $\sqrt{stuff}$? Thanks!
Wed Jul 22, 2009 6:26 pm
Forum: Intermediate Algebra
Topic: how to work this problem: 3/a²+a × 2a+2/6
Replies: 5
Views: 2139

### Re: how to work this problem: 3/a²+a × 2a+2/6

Still a little vague. As written you could mean: \frac{3}{a^2} + (a)\left(\frac{2a+2}{6}\right) or \frac{3}{a^2+a}\left(\frac{2a+2}{6}\right) or what Stapel_eliz wrote or three or four other possibilities (English is tricky, ain't it?). So, use grouping symbols like parentheses: "3 is over (a square...
Wed Jul 22, 2009 2:31 pm
Forum: Calculus
Topic: Determine eqn of conic, given F(3,1), directrix x-1=>0, ecc.
Replies: 9
Views: 6334

### Re: Determine eqn of conic, given F(3,1), directrix x-1=>0, ecc.

Yes. You need the center and the value of a and b.
Wed Jul 22, 2009 2:31 am
Forum: Beginning Algebra
Topic: Beginning and Intermediate algebra
Replies: 6
Views: 7332

### Re: Beginning and Intermediate algebra

We're home schooling, too. My oldest is only six though, so we're a bit behind you in the curriculum! I haven't looked at the Lial books since 2001 when I came to RIT, so I don't know about the current texts. At the time, the only thing in BEG that wasn't in INT was the introductory chapters: basic ...
Wed Jul 22, 2009 2:25 am
Forum: Calculus
Topic: Determine eqn of conic, given F(3,1), directrix x-1=>0, ecc.
Replies: 9
Views: 6334

### Re: Determine eqn of conic, given F(3,1), directrix x-1=>0, ecc.

I thought the directrix was a line. So I assumed it was the line x-1=0 which implies x = 1. That is, a vertical line. If this is the case, then the center of the ellipse can't be at (1,1).

Am I misunderstanding something?
Tue Jul 21, 2009 2:06 pm
Forum: Calculus
Topic: Determine eqn of conic, given F(3,1), directrix x-1=>0, ecc.
Replies: 9
Views: 6334

### Re: Determine eqn of conic, given F(3,1), directrix x-1=>0, ecc.

I see how you got a=2 and c = sqrt(2). Then, the length of the major axis would certainly be 4. How did you translate this information into your equation? What steps did you follow?