How to write $frac{x}{x^2+1}$ in terms of $frac{sqrt{x}}{x+1}$?
$begingroup$
I want to rewrite $$frac{x}{x^2+1}$$ in terms of $$frac{sqrt{x}}{x+1}$$
Soo ... I must say
$$frac{sqrt{x}}{x+1}=y$$
Then write $x$ in terms of $y$ ,but how?
algebra-precalculus
$endgroup$
add a comment |
$begingroup$
I want to rewrite $$frac{x}{x^2+1}$$ in terms of $$frac{sqrt{x}}{x+1}$$
Soo ... I must say
$$frac{sqrt{x}}{x+1}=y$$
Then write $x$ in terms of $y$ ,but how?
algebra-precalculus
$endgroup$
$begingroup$
Write $x=u^2$ and solve the quadratic equation? [Hint: the final result is $frac{y^2}{1-2 y^2}$]
$endgroup$
– AccidentalFourierTransform
Dec 9 '18 at 19:30
add a comment |
$begingroup$
I want to rewrite $$frac{x}{x^2+1}$$ in terms of $$frac{sqrt{x}}{x+1}$$
Soo ... I must say
$$frac{sqrt{x}}{x+1}=y$$
Then write $x$ in terms of $y$ ,but how?
algebra-precalculus
$endgroup$
I want to rewrite $$frac{x}{x^2+1}$$ in terms of $$frac{sqrt{x}}{x+1}$$
Soo ... I must say
$$frac{sqrt{x}}{x+1}=y$$
Then write $x$ in terms of $y$ ,but how?
algebra-precalculus
algebra-precalculus
asked Dec 9 '18 at 19:24
user602338user602338
1607
1607
$begingroup$
Write $x=u^2$ and solve the quadratic equation? [Hint: the final result is $frac{y^2}{1-2 y^2}$]
$endgroup$
– AccidentalFourierTransform
Dec 9 '18 at 19:30
add a comment |
$begingroup$
Write $x=u^2$ and solve the quadratic equation? [Hint: the final result is $frac{y^2}{1-2 y^2}$]
$endgroup$
– AccidentalFourierTransform
Dec 9 '18 at 19:30
$begingroup$
Write $x=u^2$ and solve the quadratic equation? [Hint: the final result is $frac{y^2}{1-2 y^2}$]
$endgroup$
– AccidentalFourierTransform
Dec 9 '18 at 19:30
$begingroup$
Write $x=u^2$ and solve the quadratic equation? [Hint: the final result is $frac{y^2}{1-2 y^2}$]
$endgroup$
– AccidentalFourierTransform
Dec 9 '18 at 19:30
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
HINT
We have
$$frac{sqrt{x}}{x+1}=y iff yx-sqrt x+y=0 quad sqrt x=frac{1pmsqrt{1-4y^2}}{2y}$$
$endgroup$
$begingroup$
Gimusi sorry. But I am completely confused!
$endgroup$
– user602338
Dec 9 '18 at 19:44
$begingroup$
@user602338 We can consider $yx-sqrt x+y=0$ as a qudratic equation and from here obtain $sqrt x$. It seems that for any $0<y<frac12$we have 2 solutions for $sqrt x$ and one for $y=frac12$. From $sqrt x>0$ we can determine $x$ and $x^2$.
$endgroup$
– gimusi
Dec 9 '18 at 19:48
$begingroup$
Would you please define $a,b,c$ in this quadratic equation?
$endgroup$
– user602338
Dec 9 '18 at 19:50
$begingroup$
@user602338 What do you think they could be $ycdot (sqrt x)^2-1cdot (sqrt x)+y=0$?
$endgroup$
– gimusi
Dec 9 '18 at 19:53
$begingroup$
Oh yes. That's it! Thanks! Just one more problem. How did you find range of $y$ and $sqrt{x}$?
$endgroup$
– user602338
Dec 9 '18 at 19:55
|
show 4 more comments
$begingroup$
$$frac{sqrt{x}}{x+1} = y$$ implies $$y^{-2} = x + 2 + x^{-1},$$ so that $$x + x^{-1} = y^{-2} - 2.$$ But $$frac{x}{x^2 + 1} = (x + x^{-1})^{-1} = (y^{-2} - 2)^{-1}.$$
$endgroup$
$begingroup$
Can you explain first part of your answer please?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
How did you square both sides?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
@user602338 Why don’t you try showing the first step now that you have seen it? What transformations do you need to apply?
$endgroup$
– heropup
Dec 9 '18 at 19:56
$begingroup$
Ok thanks! I solved the puzzle!
$endgroup$
– user602338
Dec 9 '18 at 19:58
$begingroup$
@user602338 persistence and practice is a big part of learning. Don’t give up so easily. As you have now seen, you figured out how to do the first part, so it is not as if you are totally helpless. You simply need to exercise your skills and your mathematical reasoning will become more sophisticated the more you work at it.
$endgroup$
– heropup
Dec 9 '18 at 20:09
add a comment |
Your Answer
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
HINT
We have
$$frac{sqrt{x}}{x+1}=y iff yx-sqrt x+y=0 quad sqrt x=frac{1pmsqrt{1-4y^2}}{2y}$$
$endgroup$
$begingroup$
Gimusi sorry. But I am completely confused!
$endgroup$
– user602338
Dec 9 '18 at 19:44
$begingroup$
@user602338 We can consider $yx-sqrt x+y=0$ as a qudratic equation and from here obtain $sqrt x$. It seems that for any $0<y<frac12$we have 2 solutions for $sqrt x$ and one for $y=frac12$. From $sqrt x>0$ we can determine $x$ and $x^2$.
$endgroup$
– gimusi
Dec 9 '18 at 19:48
$begingroup$
Would you please define $a,b,c$ in this quadratic equation?
$endgroup$
– user602338
Dec 9 '18 at 19:50
$begingroup$
@user602338 What do you think they could be $ycdot (sqrt x)^2-1cdot (sqrt x)+y=0$?
$endgroup$
– gimusi
Dec 9 '18 at 19:53
$begingroup$
Oh yes. That's it! Thanks! Just one more problem. How did you find range of $y$ and $sqrt{x}$?
$endgroup$
– user602338
Dec 9 '18 at 19:55
|
show 4 more comments
$begingroup$
HINT
We have
$$frac{sqrt{x}}{x+1}=y iff yx-sqrt x+y=0 quad sqrt x=frac{1pmsqrt{1-4y^2}}{2y}$$
$endgroup$
$begingroup$
Gimusi sorry. But I am completely confused!
$endgroup$
– user602338
Dec 9 '18 at 19:44
$begingroup$
@user602338 We can consider $yx-sqrt x+y=0$ as a qudratic equation and from here obtain $sqrt x$. It seems that for any $0<y<frac12$we have 2 solutions for $sqrt x$ and one for $y=frac12$. From $sqrt x>0$ we can determine $x$ and $x^2$.
$endgroup$
– gimusi
Dec 9 '18 at 19:48
$begingroup$
Would you please define $a,b,c$ in this quadratic equation?
$endgroup$
– user602338
Dec 9 '18 at 19:50
$begingroup$
@user602338 What do you think they could be $ycdot (sqrt x)^2-1cdot (sqrt x)+y=0$?
$endgroup$
– gimusi
Dec 9 '18 at 19:53
$begingroup$
Oh yes. That's it! Thanks! Just one more problem. How did you find range of $y$ and $sqrt{x}$?
$endgroup$
– user602338
Dec 9 '18 at 19:55
|
show 4 more comments
$begingroup$
HINT
We have
$$frac{sqrt{x}}{x+1}=y iff yx-sqrt x+y=0 quad sqrt x=frac{1pmsqrt{1-4y^2}}{2y}$$
$endgroup$
HINT
We have
$$frac{sqrt{x}}{x+1}=y iff yx-sqrt x+y=0 quad sqrt x=frac{1pmsqrt{1-4y^2}}{2y}$$
answered Dec 9 '18 at 19:37
gimusigimusi
92.8k84494
92.8k84494
$begingroup$
Gimusi sorry. But I am completely confused!
$endgroup$
– user602338
Dec 9 '18 at 19:44
$begingroup$
@user602338 We can consider $yx-sqrt x+y=0$ as a qudratic equation and from here obtain $sqrt x$. It seems that for any $0<y<frac12$we have 2 solutions for $sqrt x$ and one for $y=frac12$. From $sqrt x>0$ we can determine $x$ and $x^2$.
$endgroup$
– gimusi
Dec 9 '18 at 19:48
$begingroup$
Would you please define $a,b,c$ in this quadratic equation?
$endgroup$
– user602338
Dec 9 '18 at 19:50
$begingroup$
@user602338 What do you think they could be $ycdot (sqrt x)^2-1cdot (sqrt x)+y=0$?
$endgroup$
– gimusi
Dec 9 '18 at 19:53
$begingroup$
Oh yes. That's it! Thanks! Just one more problem. How did you find range of $y$ and $sqrt{x}$?
$endgroup$
– user602338
Dec 9 '18 at 19:55
|
show 4 more comments
$begingroup$
Gimusi sorry. But I am completely confused!
$endgroup$
– user602338
Dec 9 '18 at 19:44
$begingroup$
@user602338 We can consider $yx-sqrt x+y=0$ as a qudratic equation and from here obtain $sqrt x$. It seems that for any $0<y<frac12$we have 2 solutions for $sqrt x$ and one for $y=frac12$. From $sqrt x>0$ we can determine $x$ and $x^2$.
$endgroup$
– gimusi
Dec 9 '18 at 19:48
$begingroup$
Would you please define $a,b,c$ in this quadratic equation?
$endgroup$
– user602338
Dec 9 '18 at 19:50
$begingroup$
@user602338 What do you think they could be $ycdot (sqrt x)^2-1cdot (sqrt x)+y=0$?
$endgroup$
– gimusi
Dec 9 '18 at 19:53
$begingroup$
Oh yes. That's it! Thanks! Just one more problem. How did you find range of $y$ and $sqrt{x}$?
$endgroup$
– user602338
Dec 9 '18 at 19:55
$begingroup$
Gimusi sorry. But I am completely confused!
$endgroup$
– user602338
Dec 9 '18 at 19:44
$begingroup$
Gimusi sorry. But I am completely confused!
$endgroup$
– user602338
Dec 9 '18 at 19:44
$begingroup$
@user602338 We can consider $yx-sqrt x+y=0$ as a qudratic equation and from here obtain $sqrt x$. It seems that for any $0<y<frac12$we have 2 solutions for $sqrt x$ and one for $y=frac12$. From $sqrt x>0$ we can determine $x$ and $x^2$.
$endgroup$
– gimusi
Dec 9 '18 at 19:48
$begingroup$
@user602338 We can consider $yx-sqrt x+y=0$ as a qudratic equation and from here obtain $sqrt x$. It seems that for any $0<y<frac12$we have 2 solutions for $sqrt x$ and one for $y=frac12$. From $sqrt x>0$ we can determine $x$ and $x^2$.
$endgroup$
– gimusi
Dec 9 '18 at 19:48
$begingroup$
Would you please define $a,b,c$ in this quadratic equation?
$endgroup$
– user602338
Dec 9 '18 at 19:50
$begingroup$
Would you please define $a,b,c$ in this quadratic equation?
$endgroup$
– user602338
Dec 9 '18 at 19:50
$begingroup$
@user602338 What do you think they could be $ycdot (sqrt x)^2-1cdot (sqrt x)+y=0$?
$endgroup$
– gimusi
Dec 9 '18 at 19:53
$begingroup$
@user602338 What do you think they could be $ycdot (sqrt x)^2-1cdot (sqrt x)+y=0$?
$endgroup$
– gimusi
Dec 9 '18 at 19:53
$begingroup$
Oh yes. That's it! Thanks! Just one more problem. How did you find range of $y$ and $sqrt{x}$?
$endgroup$
– user602338
Dec 9 '18 at 19:55
$begingroup$
Oh yes. That's it! Thanks! Just one more problem. How did you find range of $y$ and $sqrt{x}$?
$endgroup$
– user602338
Dec 9 '18 at 19:55
|
show 4 more comments
$begingroup$
$$frac{sqrt{x}}{x+1} = y$$ implies $$y^{-2} = x + 2 + x^{-1},$$ so that $$x + x^{-1} = y^{-2} - 2.$$ But $$frac{x}{x^2 + 1} = (x + x^{-1})^{-1} = (y^{-2} - 2)^{-1}.$$
$endgroup$
$begingroup$
Can you explain first part of your answer please?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
How did you square both sides?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
@user602338 Why don’t you try showing the first step now that you have seen it? What transformations do you need to apply?
$endgroup$
– heropup
Dec 9 '18 at 19:56
$begingroup$
Ok thanks! I solved the puzzle!
$endgroup$
– user602338
Dec 9 '18 at 19:58
$begingroup$
@user602338 persistence and practice is a big part of learning. Don’t give up so easily. As you have now seen, you figured out how to do the first part, so it is not as if you are totally helpless. You simply need to exercise your skills and your mathematical reasoning will become more sophisticated the more you work at it.
$endgroup$
– heropup
Dec 9 '18 at 20:09
add a comment |
$begingroup$
$$frac{sqrt{x}}{x+1} = y$$ implies $$y^{-2} = x + 2 + x^{-1},$$ so that $$x + x^{-1} = y^{-2} - 2.$$ But $$frac{x}{x^2 + 1} = (x + x^{-1})^{-1} = (y^{-2} - 2)^{-1}.$$
$endgroup$
$begingroup$
Can you explain first part of your answer please?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
How did you square both sides?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
@user602338 Why don’t you try showing the first step now that you have seen it? What transformations do you need to apply?
$endgroup$
– heropup
Dec 9 '18 at 19:56
$begingroup$
Ok thanks! I solved the puzzle!
$endgroup$
– user602338
Dec 9 '18 at 19:58
$begingroup$
@user602338 persistence and practice is a big part of learning. Don’t give up so easily. As you have now seen, you figured out how to do the first part, so it is not as if you are totally helpless. You simply need to exercise your skills and your mathematical reasoning will become more sophisticated the more you work at it.
$endgroup$
– heropup
Dec 9 '18 at 20:09
add a comment |
$begingroup$
$$frac{sqrt{x}}{x+1} = y$$ implies $$y^{-2} = x + 2 + x^{-1},$$ so that $$x + x^{-1} = y^{-2} - 2.$$ But $$frac{x}{x^2 + 1} = (x + x^{-1})^{-1} = (y^{-2} - 2)^{-1}.$$
$endgroup$
$$frac{sqrt{x}}{x+1} = y$$ implies $$y^{-2} = x + 2 + x^{-1},$$ so that $$x + x^{-1} = y^{-2} - 2.$$ But $$frac{x}{x^2 + 1} = (x + x^{-1})^{-1} = (y^{-2} - 2)^{-1}.$$
answered Dec 9 '18 at 19:34
heropupheropup
63.6k762102
63.6k762102
$begingroup$
Can you explain first part of your answer please?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
How did you square both sides?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
@user602338 Why don’t you try showing the first step now that you have seen it? What transformations do you need to apply?
$endgroup$
– heropup
Dec 9 '18 at 19:56
$begingroup$
Ok thanks! I solved the puzzle!
$endgroup$
– user602338
Dec 9 '18 at 19:58
$begingroup$
@user602338 persistence and practice is a big part of learning. Don’t give up so easily. As you have now seen, you figured out how to do the first part, so it is not as if you are totally helpless. You simply need to exercise your skills and your mathematical reasoning will become more sophisticated the more you work at it.
$endgroup$
– heropup
Dec 9 '18 at 20:09
add a comment |
$begingroup$
Can you explain first part of your answer please?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
How did you square both sides?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
@user602338 Why don’t you try showing the first step now that you have seen it? What transformations do you need to apply?
$endgroup$
– heropup
Dec 9 '18 at 19:56
$begingroup$
Ok thanks! I solved the puzzle!
$endgroup$
– user602338
Dec 9 '18 at 19:58
$begingroup$
@user602338 persistence and practice is a big part of learning. Don’t give up so easily. As you have now seen, you figured out how to do the first part, so it is not as if you are totally helpless. You simply need to exercise your skills and your mathematical reasoning will become more sophisticated the more you work at it.
$endgroup$
– heropup
Dec 9 '18 at 20:09
$begingroup$
Can you explain first part of your answer please?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
Can you explain first part of your answer please?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
How did you square both sides?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
How did you square both sides?
$endgroup$
– user602338
Dec 9 '18 at 19:38
$begingroup$
@user602338 Why don’t you try showing the first step now that you have seen it? What transformations do you need to apply?
$endgroup$
– heropup
Dec 9 '18 at 19:56
$begingroup$
@user602338 Why don’t you try showing the first step now that you have seen it? What transformations do you need to apply?
$endgroup$
– heropup
Dec 9 '18 at 19:56
$begingroup$
Ok thanks! I solved the puzzle!
$endgroup$
– user602338
Dec 9 '18 at 19:58
$begingroup$
Ok thanks! I solved the puzzle!
$endgroup$
– user602338
Dec 9 '18 at 19:58
$begingroup$
@user602338 persistence and practice is a big part of learning. Don’t give up so easily. As you have now seen, you figured out how to do the first part, so it is not as if you are totally helpless. You simply need to exercise your skills and your mathematical reasoning will become more sophisticated the more you work at it.
$endgroup$
– heropup
Dec 9 '18 at 20:09
$begingroup$
@user602338 persistence and practice is a big part of learning. Don’t give up so easily. As you have now seen, you figured out how to do the first part, so it is not as if you are totally helpless. You simply need to exercise your skills and your mathematical reasoning will become more sophisticated the more you work at it.
$endgroup$
– heropup
Dec 9 '18 at 20:09
add a comment |
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$begingroup$
Write $x=u^2$ and solve the quadratic equation? [Hint: the final result is $frac{y^2}{1-2 y^2}$]
$endgroup$
– AccidentalFourierTransform
Dec 9 '18 at 19:30