Have a look here,
http://www.mathhelpforum.com/math-he...tml#post676002
For the second one you have
So define , where is this function less than zero?
Sorry for the first thread. Anyways, I am really struggling with these problems.
I will post two for now, hopefully the work here will help me figure out the others.
First, one division problem with several exponents.
{ (x^2 - 1)^1/2 - (x^2 - 1)^-1/2 (2 - x^2) } / (x^2 - 1) = 0
The hint is be sure to simplify first. I have no idea how to start. Do I take the negative exponents to the bottom? Or cancel out? No clue.
Second.
| 1 - 4x | - 7 < or = - 2
I'm not remembering the rules on abs. val. when there are variables in the bars, I know for |-2| it just becomes 2, |2| is 2, etc. But when there's variables in there, I'm not sure, so a link or explanation of that would really help.
Thanks in advance, I hope this satisfies the rules.
Have a look here,
http://www.mathhelpforum.com/math-he...tml#post676002
For the second one you have
So define , where is this function less than zero?
| 1 - 4x | - 7 < or = - 2
First check where the two sides are equal.
Then either 1- 4x= 5 or 1- 4x= -5.
If 1- 4x= 5, -4x= 4, x= -1. If 1- 4x= -5, -4x= -6, x= 3/2.
x= -5 and x= 3/2 divides the real line into three intervals: , , [tex]3\le x[/itex].
x= -6 is in the first interval and if x= -6, |1- 4x|- 7= |1+ 24|- 7= 25- 7= 18> -2. x= -6 does NOT satisfy the inequality so no x< -5 does. Of course, x= -5 makes the two sides equal.
If x= 0, which is between -5 and 3/2, then |1- 4x|- 7= |1- 0|- 7= -7< 2. x= 0 DOES satisfy the inequality so any x in does also.
If x= 2, which is larger than 3/2, then |1- 4x|- 7= |1- 8|- 7= 7- 7= 0> -2. x= 2 does NOT satisfy the inequality so any x larger than 3/2 does not.
The solution set is .
I'm not remembering the rules on abs. val. when there are variables in the bars, I know for |-2| it just becomes 2, |2| is 2, etc. But when there's variables in there, I'm not sure, so a link or explanation of that would really help.
Thanks in advance, I hope this satisfies the rules.
Thanks for the help guys. I was able to work them out and get the right answers. Some of the stuff is starting to come back. Anyways, I know have some questions on this stuff.
To be honest, not really sure where to go or what exactly to do. All I'm really getting is that [I figure] there is something to do with sin of pi/2 being 1 that is involved, but really not sure.
Here.
1. Start by noting that . How can you use this to help you in the first problem?
2. Start by using the double angle identity for and the triple angle identity for .
3. Start by expanding .
Thanks, got it.
Really appreciate all the help. Btw just so you guys know you are not doing all my homework haha, I do about 10-15 problems in between these.
Here's the other two I don't know how to do. I completely forgot rules of trig so I don't know how to cancel stuff out or the trig formulas.
For the first one consider
For the second make and apply the compound angle formula
For the third one, expand the LHS, what do you get?
Finally
Maybe time you started a new thread?