02 Jul 2013, 7:54 am
ruveyn wrote:
Salome wrote:
Ok I'm done feeling sorry for myself for being completely hopeless and I've done some thinking.
I decided that it doesn't matter that I suck at maths and maybe even fail the course, I'm going to take it anyway. I mean I am learning new things and that was the whole point of taking the course in the first place.
Hopefully I haven't scared of all you math geniuses incase I need to ask more questions!
I decided that it doesn't matter that I suck at maths and maybe even fail the course, I'm going to take it anyway. I mean I am learning new things and that was the whole point of taking the course in the first place.
Hopefully I haven't scared of all you math geniuses incase I need to ask more questions!
Ask. Just do not ask for the answers to your homework problems.
ruveyn
I wasn't aware that I did. I needed help breaking it down and every step explained (why it's done that way) I apologize if that was wrong!
02 Jul 2013, 11:54 am
02 Jul 2013, 12:06 pm
02 Jul 2013, 12:22 pm
02 Jul 2013, 12:55 pm
03 Jul 2013, 2:44 pm
03 Jul 2013, 4:56 pm
03 Jul 2013, 5:09 pm
03 Jul 2013, 5:36 pm
03 Jul 2013, 5:42 pm
03 Jul 2013, 5:53 pm
03 Jul 2013, 6:24 pm
03 Jul 2013, 8:43 pm
04 Jul 2013, 9:28 am
04 Jul 2013, 9:32 am
04 Jul 2013, 10:28 am
Dhp wrote:
Hi, Salome. I hope you're doing well. I'm afraid that you have made three errors in this problem.
The first is that instead of dividing by x (even though all three terms had an x in common), you need to factor out the x so that you have this:
Note: for notational purposes, I will use the ^ sign to represent an exponent...like x^2 means x squared, and x^3 means x cubed.
The original problem then would look like this:
x^3 - 4x^2 - 5x = 0 (confusing, isn't it? Well, thanks to Bill Gates for not providing us with a good math text editor that can work anywhere instead of just Microsoft Word...heh)
Now, since all three terms have an x in common, we can factor out an x so it would now look like this:
x(x^2 - 4x - 5) = 0. Why the &$% would you do that? Because x = 0 is one solution to that equation. Look -> 0(0^2 - 4(0) - 5) = 0.
When you divided that whole thing by x, you eliminated one of the solutions. But please don't leave x= 0 in the cold cold snow! He has a wife and family! Why, everyday he has to walk 10 miles to the bus barefoot in the snow! Just kidding around...
The second mistake is that on the third line down on your step by step written out page, you have to follow the ordering of stuff. You need to divide 4 by 2 first before you square it under the square root. Then you'll get 2 squared, which is 4.
But wait, there's more (shuts off the TV because of the salesman's annoying voice)...
Underneath that radical, you will then have 4 + 5. But that equals 9, and the square root of 9 is 3. So now you should have this:
x = 0 (don't forget him), x = 2 +/- (that's plus or minus) 3. This means that your answer is 0, -1, and 5.
What? Is it possible to have three solutions? Of course it is. It is a cubic equation after all, and the most solutions you can have is 3. (jokingly) 3 is the number that you shalt count, and the number that you shalt count is 3...
I only hope that this helps you, Salome. If not, please let me know how I can help. Have a great evening.
The first is that instead of dividing by x (even though all three terms had an x in common), you need to factor out the x so that you have this:
Note: for notational purposes, I will use the ^ sign to represent an exponent...like x^2 means x squared, and x^3 means x cubed.
The original problem then would look like this:
x^3 - 4x^2 - 5x = 0 (confusing, isn't it? Well, thanks to Bill Gates for not providing us with a good math text editor that can work anywhere instead of just Microsoft Word...heh)
Now, since all three terms have an x in common, we can factor out an x so it would now look like this:
x(x^2 - 4x - 5) = 0. Why the &$% would you do that? Because x = 0 is one solution to that equation. Look -> 0(0^2 - 4(0) - 5) = 0.
When you divided that whole thing by x, you eliminated one of the solutions. But please don't leave x= 0 in the cold cold snow! He has a wife and family! Why, everyday he has to walk 10 miles to the bus barefoot in the snow! Just kidding around...
The second mistake is that on the third line down on your step by step written out page, you have to follow the ordering of stuff. You need to divide 4 by 2 first before you square it under the square root. Then you'll get 2 squared, which is 4.
But wait, there's more (shuts off the TV because of the salesman's annoying voice)...
Underneath that radical, you will then have 4 + 5. But that equals 9, and the square root of 9 is 3. So now you should have this:
x = 0 (don't forget him), x = 2 +/- (that's plus or minus) 3. This means that your answer is 0, -1, and 5.
What? Is it possible to have three solutions? Of course it is. It is a cubic equation after all, and the most solutions you can have is 3. (jokingly) 3 is the number that you shalt count, and the number that you shalt count is 3...
I only hope that this helps you, Salome. If not, please let me know how I can help. Have a great evening.
Hello! Thank you for your explanation! I almost get it
However, could you write it out step by step like I did because I don't understand how you write out what you said. For me to understand this it needs to look the same as what I put up there but the correct way. I'm not good enough at maths to understand if I can't clearly see the connections.
Also now I'm thinking that one of my previous equations was solved wrong because I realised I didn't do the parentheses first grrrr!
