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answered: 49 problems
Jump to solutions: 0..29 , 30..59, >>NextRational-functions/241541: I'm trying to graph f(x)=x/x^2+1
I need to include all the intercepts and asymptotes. I worked out that the horizontal asymptote is y=0 and that the y-intercept is (0,0). I'm having problems with the rest, though. 1 solutions
Answer 176906 by jsmallt9(597) on 2009-11-22 05:04:15 (Show Source):
You can put this solution on YOUR website!You've done very well so far. You've found all there is to find except - since f(-x) = -f(x), the graph will be symmetric about the origin.
- if you know Calculus, you can find
- local maximum and minimum points, if any
- where the graph is increasing and where it is decreasing
by finding and using the first and second derivatives. - you can build a table of values and plot the points.
Here's a graph:
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Graphs/241542: Here's my question:
Sketch the graph of each function or relation and state the domain and range.
Y = │x│ - 4
I can figure it out on the graphing software once I figure out the problem. I am not sure how to figure out a problem like this. Can someone help me please?
Thanks. 1 solutions
Answer 176905 by jsmallt9(597) on 2009-11-22 04:43:16 (Show Source):
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Quadratic_Equations/241545: The height, h, of a cricket ball above the ground after t seconds is given by the eqaution h = 20t - 5t^2.
When is the ball 25 metres above the ground?
Need help! Don't know what to do! Maths exam tomorrow 1 solutions
Answer 176904 by jsmallt9(597) on 2009-11-22 04:14:34 (Show Source):
You can put this solution on YOUR website!So you are given the equation and the height and you've been asked to find the time. You just put the height into the equation and then use Algebra to solve for the time:

To solve this we need to recognize that, because of the  , it is a quadratic equation.
To solve a quadratic equation you get one side equal to zero and then factor it of use the Quadratic formula. So we will start by subtracting 20 from each side (the quickest way to get one side to be zero):

(I've also rearranged the terms to make the factoring (or use of the Quadratic formula easier.) When factoring, always start by factoring out the Greates COmmon Factor (GCF) (unless it is a 1). The GCF here is 5:

We could factor the trinomial factor as it is but I like having a positive leading coefficient so I will factor out a -1. (I could have factored out a -5 earlier but I didn't want to confuse you.)

The trinomial is now more recognizably factorable. It fits the pattern:  . So it factors into:

According to the Zero Product Property this product can be zero only if one of the factors is zero. 5 can't be zero and neither can -1. But t-2 can:
t-2 = 0
t = 2
So the cricket ball is 25 meters (metres in the UK) high after 2 seconds. (If you think about it, this must be the maximum height of the cricket ball. The cricket ball will be at the various heights once on the way up and once on the way down. So there should be two times for each height. The exception is the maximum height. The maximum height is achieved only once, in the middle of the flight. This is why we only got one time for this height.)
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Graphs/241527: Slope-Intercept Form?
In laymans terms, can you explain the simplest way I can learn how to identify the slope and y intercept?
Example 2x-y=12
I have no idea where to even start?? 2 solutions
Answer 176903 by MathTherapy(337) on 2009-11-22 01:50:23 (Show Source):
You can put this solution on YOUR website!Slope-Intercept Form?
In laymans terms, can you explain the simplest way I can learn how to identify the slope and y intercept?
Example 2x-y=12
I have no idea where to even start??
For any equation to be in slope-intercept form, it has to be in the form, y = mx + b, where m, or the coefficient of x is the slope, and " + b" is the y-intercept.
Now, let's take your example, 2x - y = 12
We have to first of all put this equation in slope-intercept form
2x - y = 12 -----> - y = - 2x + 12 (subtract 2x from both sides of equation)
- y = - 2x + 12 ------> y = 2x - 12 (divide each side of equation by - 1)
Now that we have the equation in slope-intercept form, y = 2x - 12 indicates that m or slope of the equation is  , and " + b" or the y-intercept of the equation is
Answer 176898 by BayAreaRed(2) on 2009-11-21 23:40:30 (Show Source):
You can put this solution on YOUR website!The Quick Study reference guide has a very simple explanation and I quote it here. The breakdown into sentences is mine. Read each sentence and MAKE SURE YOU UNDERSTAND IT before you go on to the next.
"The slope of a line can loosely be described as the slant of the line.
If the line slants up on the right end of the line, then the slope will be a positive number.
If the line slants up on the left end of the line, then the slope will be a negative number.
If the line is horizontal, then the slope is zero.
If the line is vertical, then the line has no slope; it is undefined."
Now... once you understand that, then go on to this formula:
If the line is NOT vertical, then slope (indicated by the letter "m") can be found using two distinct points: A and B. Coordinates are written (x,y) with x being the horizontal point and y being the vertical point. For instance, if A's coordinates (x) are (5,6) and B's coordinates (y) are (7,3), then you would plug them into this formula:
m = (y2 - y1) / (x2 - x1) = (change in y) / (change in x) = rise / run
This is a complicated formula to write here, but Google "slope of a line formula" and you should see a better rendition of the formula.
In the case I stated above, you would plug A's coordinates in:
m = (3 - 6) over or divided by (7 - 5) = (change in y) over or divided by (change in x) = "rise" over or divided by "run"
I'm sorry I cannot give you a better explanation here, but this is one of those concepts that is difficult to explain sometimes. Here is a link on this site that I use for my students (I am a tutor) that might help explain it better.
http://www.algebra.com/algebra/homework/Graphs/Graphing-by-Slope-Intercept-Method.lesson
I hope this helps. :)
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Quadratic_Equations/241529: if the vertex of the graph of a quadratic function lies in quadrant III and the graph opens down, how many x-intercepts doe sthe graph have? 1 solutions
Answer 176900 by rapaljer(3625) on 2009-11-22 00:30:14 (Show Source):
You can put this solution on YOUR website!None!! If the vertex is in Q III and opens down, it doesn't touch the x axis. NO INTERCEPTS!!
Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus
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Functions/241531: evaluate the function at the given value of the independent variable and simplify: g(x)=4x-3;g(x+1)
i believe the answer is 4x+1 but am not sure. please advise
1 solutions
Answer 176899 by rapaljer(3625) on 2009-11-22 00:27:52 (Show Source):
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Human-and-algebraic-language/241393: if tom, james, and tony buy an 18in. sandwich. tom gives james one half of what tom gets and tony gets three fourths of what tom gets. what is the length of each persons sandwich. 1 solutions
Answer 176897 by College Student(217) on 2009-11-21 23:25:19 (Show Source):
You can put this solution on YOUR website!Let Tom = x
James = 1/2 x
Tony = 3/4 x
Total lenght of sandwich = 18 inches
.
Our equation now becomes: 
Since your denominators are 1, 2, and 4... the LCD is 4.
The new equation with common denominators becomes:

Then add numerators:

Now multiply by the fraction's reciprocal on both sides to determine the value of x.

.
Tom's sandwich is 8 inches long.
James's sandwich is (1/2)*8=4 inches long.
Tony's sandwich is (3/4)*8=6 inches long.
.
If we add all pieces, we get:
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Expressions-with-variables/241503: I need help with solving this equation.Find all numbers for which the rational expression is undefined
n^3-7n/n^2-4 (this problem is division) 1 solutions
Answer 176894 by College Student(217) on 2009-11-21 22:58:47 (Show Source):
You can put this solution on YOUR website!In order for a fraction to be undefine, its denominator would equal to zero. So, let the denominator (by itself) equal to zero and find the solution(s).
.

Take the square root on both sides of the equation to determine the value of n.

Since the square root of a number raised to the 2nd power cancel each other, we can re-write the equation like this:

This will yield two possible answers:
n=2 and n=-2
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Check:

.
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Permutations/241523: A poker hand consists of five cards from a standard deck of 52. Find the number of different poker hands of straight (five cards of consecutive denominations: A, 2, 3, 4, 5 up through 10, J, Q, K, A, not all of the same suit). (Note that the Ace counts either as a 1 or as the denomination above King.)
1 solutions
Answer 176893 by stanbon(26297) on 2009-11-21 22:53:35 (Show Source):
You can put this solution on YOUR website!A poker hand consists of five cards from a standard deck of 52.
Find the number of different poker hands of straight (five cards of consecutive denominations: A, 2, 3, 4, 5 up through 10, J, Q, K, A, not all of the same suit). (Note that the Ace counts either as a 1 or as the denomination above
King.
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Pick a lowest starting card type: 10 ways
Pick that lowest card and each of the next 4: 4^5 = 1024 ways
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Total number of straights: 10*1024= 10,240
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Cheers,
stan H.
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Money_Word_Problems/241518: P dollars invested at interest rate r compounded annually for 5 years increases to an amount A = P(1 + r)^5. If an investment of $1000 is to increase to an amount greater than $1400 in 5 years, then the interest rate must be greater than what percentage? 1 solutions
Answer 176892 by josmiceli(3013) on 2009-11-21 22:47:36 (Show Source):
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Travel_Word_Problems/241517: The height about the ground of an object t seconds after it is launched vertically upward is h(t)=100t-5t^2 meters
What is the velocity of the object after 3 seconds 1 solutions
Answer 176888 by Alan3354(6097) on 2009-11-21 22:34:57 (Show Source):
You can put this solution on YOUR website!The height about the ground of an object t seconds after it is launched vertically upward is h(t)=100t-5t^2 meters
What is the velocity of the object after 3 seconds
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h'(t) = 100 - 10t
h'(3) = 70 m/sec
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Did you mean to ask the height? If so,
h(3) = 100*3 - 5*9
h(3) = 255 meters, going up at 70 meters/sec
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logarithm/241498: Solve the following equation using the Quadratic Formula.
2x²-11x-2=0
The solution set is { }
Type an exact answer, using radicals as needed. Use a comma to separate answers as needed.
1 solutions
Answer 176885 by Alan3354(6097) on 2009-11-21 22:20:08 (Show Source):
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Travel_Word_Problems/241510: You drove 56 miles on a service call for your company and it took 10 minutes longer than the return trip when you drove an average of 8 miles per hour faster. What was your average speed on the return trip? 1 solutions
Answer 176884 by stanbon(26297) on 2009-11-21 22:12:00 (Show Source):
You can put this solution on YOUR website!You drove 56 miles on a service call for your company and it took 10 minutes longer than the return trip when you drove an average of 8 miles per hour faster. What was your average speed on the return trip?
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Service Call DATA:
distance = 56 miles ; rate = x mph ; time = d/r = 56/x hrs
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Return trip DATA:
distance = 56 miles ; rate = (x+8) mph ; time = 56/(x+8) hrs
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Equation:
go time - return time = 1/6 hr
56/x - 56/(x+8) = 1/6
1/x - 1/(x+8) = 1/336
Multiply thru by 336x(x+8) to get:
336(x+8) - 336x = x(x+8)
336*8 = x^2+8x
x^2 + 8x - 2688 = 0
(x-48)(x+56) = 0
Positive solution:
x = 48 mph (rate on the service call)
x+8 = 56 mph (rate on the return)
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Cheers,
Stan H.
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Equations/240561: In one season, Kim ran 18 races. This was four fewer races than twice the number of races Kelly ran. How many races did Kelly run? 1 solutions
Answer 176882 by College Student(217) on 2009-11-21 21:59:22 (Show Source):
You can put this solution on YOUR website!Hello!
.
If Kelly ran x number of races, we can then say Kim ran 2x-4=18.
So we now solve for x to determine how many races Kelly ran.
.

.
Since Kelly is x, she ran 11 races.
.
Let's check for Kim's number of races.
 ... it checks!
.
Done! :)
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Polynomials-and-rational-expressions/241505: Compute the discriminant. Then determine the number and type of solutions for the given equation.
4x²-2x+1=0
What is the discriminant?
1 solutions
Answer 176881 by stanbon(26297) on 2009-11-21 21:52:37 (Show Source):
You can put this solution on YOUR website!Compute the discriminant. Then determine the number and type of solutions for the given equation.
4x²-2x+1=0
a = 4 ; b = -2 ; c = 1
What is the discriminant?
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discriminant = b^2-4ac
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Your Problem:
D = (-2)^2 - 4*4*1 = 4-16 = -12
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Since the discriminant is negative
the quadratic has two complex number solutions.
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Cheers,
Stan H.
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