College Algebra Questions! (Help!) :(

[xLeeChaex]

I need help with this one, BUT i only need help with the one that says

For What values of x is f(x) < 0?

 

https://38.media.tumblr.com/3b11a98d3ca338c829b6855a6b95e222/tumblr_nf3phwgy5k1r9m8d9o1_1280.jpg

 

 

As for this one, I want to know if these three questions are right?

If not would u care to explain??

 

https://38.media.tumblr.com/4dad047f36ed784ec18b2d521daa9bd7/tumblr_nf3phwgy5k1r9m8d9o2_1280.jpg

 

Lastly, for this one i need help with the graphing part but i ONLY want to know how u graph x+2y≥1

its a fraction and its been giving me difficulties lol

As u can see, i did it but i stopped bc idk wtf i am doing lmao

 

https://33.media.tumblr.com/604eca0c62bfe0193732f4a7b117a114/tumblr_nf3phwgy5k1r9m8d9o3_1280.jpg

[byeol]

I'm so stupid when it comes to this, maths and mostly everything related to school 

[Athena]

For the first one the answer is 2, because (2,-2) is the only point that has a negative y-coordinate. 

 

For the last one if you get 'y' alone the equation is y â‰¥ - (1/2)x + (1/2). 

Graph it like you normally would: y = -(1/2)x + (1/2)

 

Make sure the line you graphed is a solid line.

 

Then since the equation is greater or less you would shade the empty space above the line that you just graphed.

[fiestargossip]

For the first one the answer is 2, because (2,-2) is the only point that has a negative y-coordinate. 

 

For the last one if you get 'y' alone the equation is y â‰¥ - (1/2)x + (1/2). 

Graph it like you normally would: y = -(1/2)x + (1/2)

 

Make sure the line you graphed is a solid line.

 

Then since the equation is greater or less you would shade the empty space above the line that you just graphed.

For the first one, aren't all x values between 0 and 4 negative though?

[xLeeChaex]

For the first one the answer is 2, because (2,-2) is the only point that has a negative y-coordinate. 

 

For the last one if you get 'y' alone the equation is y â‰¥ - (1/2)x + (1/2). 

Graph it like you normally would: y = -(1/2)x + (1/2)

 

Make sure the line you graphed is a solid line.

 

Then since the equation is greater or less you would shade the empty space above the line that you just graphed.

 

But how do u graph that fraction?? i know on the yaxis its 1/2 but i do not know whats on the xaxis lol

[Silktiger]

3) Sorry if it's hard to see

but the answer is the area that I traced and shaded with black

Basically the first thing I did was rearrange all the equations in slope-intercept form, to make it easier to graph. Then, take the first one for example (the orange one), I graphed the line by itself. Then it says that y is greater than or equal to, so I shaded all the area above the line (where the y values of any point in that area will be greater than the y values of the line). I did the same thing with the other three equations. Find the places where all your shading intersects. It should be a  parallelogram/diamond shape. Then, you take into account that x and y have to be greater than or equal to zero, which means its on the axes and in the first quadrant only. So, you eliminate all the areas outside, and you get the black area that I shaded and outlined, which should be the answer

EDIT: Ooops sorry I just realized you only wanted to know how to graph one of them... mb

[..............]

For What values of x is f(x) < 0  (0,4) and f(-1) is positive.

 

A function is even if it is symmetric about the y-axis. It is odd if it is symmetric about the origin. go here for more info and exercises.

 

the graph for the third question.

 

 

[Silktiger]

But how do u graph that fraction?? i know on the yaxis its 1/2 but i do not know whats on the xaxis lol

y=(-1/2)x + (1/2)

Well if you want to find the x-intercept you can just sub in 0 for y. So it would be 0=(-1/2)x +(1/2), and the answer would be x=1. So it crosses the x-axis at (1,0).

Another way you could graph this without having to find the x-intercept is recalling that Slope= rise/run.

So (-1/2)= rise/run

Rise= -1

Run= 2

So, for every time it goes to the right 2, it goes down 1. Just stick to the first way if you're confused ^_^

[xLeeChaex]

y=(-1/2)x + (1/2)

Well if you want to find the x-intercept you can just sub in 0 for y. So it would be 0=(-1/2)x +(1/2), and the answer would be x=1. So it crosses the x-axis at (1,0).

Another way you could graph this without having to find the x-intercept is recalling that Slope= rise/run.

So (-1/2)= rise/run

Rise= -1

Run= 2

So, for every time it goes to the right 2, it goes down 1. Just stick to the first way if you're confused ^_^

 

omggg thank u so much for the explanation and the graph! :DDD

For What values of x is f(x) < 0  (0,4) and f(-1) is positive.

 

A function is even if it is symmetric about the y-axis. It is odd if it is symmetric about the origin. go here for more info and exercises.

 

the graph for the third question.

 

 

 

And thank u for the graph as well!!! :DD

[Silktiger]

omggg thank u so much for the explanation and the graph! :DDD

 

 

And thank u for the graph as well!!! :DD

NP :D

Check with someone else doing that too because I could be wrong about the graph

[xLeeChaex]

For What values of x is f(x) < 0  (0,4) and f(-1) is positive.

 

A function is even if it is symmetric about the y-axis. It is odd if it is symmetric about the origin. go here for more info and exercises.

 

the graph for the third question.

 

 

 

can i ask is the 1/2 on the y axis?

Then how u went down to the x axis??

[Athena]

For the first one, aren't all x values between 0 and 4 negative though?

oh I thought it was just asking for a specific point. Yeah then it would be 0 <x < 4

[xLeeChaex]

oh I thought it was just asking for a specific point. Yeah then it would be 0 <x < 4

 

How do u know its 0<x<4

like i dont understand that lol

[suzya]

This is college algebra? Somehow I'm pretty sure I gave this and more in 12th grade??

Anyhow, good luck with that! 

 

I really hate math, so I won't even try. But, you seem to have people here that are pretty good 

[Athena]

How do u know its 0<x<4

like i dont understand that lol

Because you have to look at the graph. When x = 1, y = - 1. When x = 2, y= - 2. When x = 3, y = -1.

 

Those y-values are the only negative ones. Therefore when x is 1, 2, or 3: f(x) is less than 0.

[..............]

can i ask is the 1/2 on the y axis?

Then how u went down to the x axis??

it became y is greater-than-and-equal-to (-1/2)x + 1/2. The (-1/2) is the slope, and (1/2) is the y-intercept. So I started from the y-intercept then moved 1 unit down and 2 units to the left and continued until i got four points. (you know the rise/run).