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Feb 5 2014 04:52pm
Sup guys, got a couple questions I couldn't figure out.

1. Solve and express the solution in interval notation

5x^2 + 3x ≥ 3z^2 + 2


2. Find an equation of a line that satisfies the given conditions

Slope 2/5 ; y-intercept 4


3. y-intercept 6 ; parallel to the line 2x + 3y + 4 = 0


4. Through (2,6) ; perpendicular to the line y=1


5. Find the domain of the function

f(x) = x^2 + 1, 0 ≤ x ≤ 5


Any help would be appreciated!
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Feb 5 2014 05:35pm
are you sure you have stated the question correctly?

what does "z" in question 1 mean?

and in question 5, are you looking for the range? the domain is given as [0,5]
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Feb 5 2014 05:43pm
Quote (JoeyMorgan619 @ Feb 5 2014 04:52pm)
1. Solve and express the solution in interval notation

5x^2 + 3x ≥ 3z^2 + 2



5x^2 + 3x ≥ 3x^2 + 2
2x^2 +3x>= +2
2x^2 +3x -2 >= 0
(2x-1)(x+2)>=0


Quote
2. Find an equation of a line that satisfies the given conditions


http://www.purplemath.com/modules/strtlneq2.htm

This post was edited by saber_x3 on Feb 5 2014 05:44pm
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Feb 5 2014 09:48pm
Quote (brmv @ Feb 5 2014 05:35pm)
are you sure you have stated the question correctly?

what does "z" in question 1 mean?

and in question 5, are you looking for the range? the domain is given as [0,5]


yes, it was supposed to be x instead of z but saber figured it out already.

as for question 5, no, it says the domain. so [0,5] is the domain?
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Feb 5 2014 10:11pm
Quote (JoeyMorgan619 @ 6 Feb 2014 03:48)
yes, it was supposed to be x instead of z but saber figured it out already.
just wanted to be sure it was not "y" asking for an answer on the plane
as for question 5, no, it says the domain.  so [0,5] is the domain?


and yes, in that formulation the domain is [0,5] because it is defined for all those values
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Feb 5 2014 10:31pm
Quote (brmv @ Feb 5 2014 10:11pm)
and yes, in that formulation the domain is [0,5] because it is defined for all those values


Sweet. Thanks a bunch!
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Feb 6 2014 10:06pm
still cannot figure out #4

please help if you can
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Feb 6 2014 10:11pm
Quote (JoeyMorgan619 @ Feb 6 2014 11:06pm)
still cannot figure out #4

please help if you can


the line y=1 is a horizontal line where the y-value is 1 for every x-value.
You should know that a line perpendicular to a horizontal line is a vertical line.
A vertical line will have the same x-value for every y-value.
Now use your given point (2,6) and take the x-value to figure out your line.
So from the given point and the fact you know it's a vertical line, you get: x=2

E: if you're having trouble following my wording, try sketching what i say line-by-line. It might help you understand it better

This post was edited by TritonV8 on Feb 6 2014 10:12pm
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Feb 9 2014 06:58pm
#4) When you need to find a line perpendicular to another line, you find the reciprocal of the
slope. So since y=1 has no slope, your answer will have no slope.

And then you plug in the numbers to the formula: (y-y1)=M(x-x1).

However, in this case you don't need to do any of that. y=1 is a straight horizontal line
at (0,2). So to find the line that is perpendicular to that, you just take the x coordinate
and that's your answer! x=2.
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