Evaluating the limit for a point on the curve
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For point p(a,b) lying on the curve $2xy^2dx + 2x^2 y dy -
tan(x^2y^2) dx =0 $;
$lim_ato -inftyb =? $
Options are:
a) $ 0$
b) $-1 $
c) $1$
d) does not exist.
Attempt:
If we observe carefully we get:
$d(x^2 y^2) = tan(x^2 y^2) dx$
$implies ln(csin x^2y^2) = x$
$implies c sin (x^2 y^2) = e^x$
Now clearly as $x to -infty ~ , e^x to 0$, so clearly $y to 0$
But answer given is d. Please let me know my mistake.
calculus
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up vote
5
down vote
favorite
For point p(a,b) lying on the curve $2xy^2dx + 2x^2 y dy -
tan(x^2y^2) dx =0 $;
$lim_ato -inftyb =? $
Options are:
a) $ 0$
b) $-1 $
c) $1$
d) does not exist.
Attempt:
If we observe carefully we get:
$d(x^2 y^2) = tan(x^2 y^2) dx$
$implies ln(csin x^2y^2) = x$
$implies c sin (x^2 y^2) = e^x$
Now clearly as $x to -infty ~ , e^x to 0$, so clearly $y to 0$
But answer given is d. Please let me know my mistake.
calculus
add a comment |Â
up vote
5
down vote
favorite
up vote
5
down vote
favorite
For point p(a,b) lying on the curve $2xy^2dx + 2x^2 y dy -
tan(x^2y^2) dx =0 $;
$lim_ato -inftyb =? $
Options are:
a) $ 0$
b) $-1 $
c) $1$
d) does not exist.
Attempt:
If we observe carefully we get:
$d(x^2 y^2) = tan(x^2 y^2) dx$
$implies ln(csin x^2y^2) = x$
$implies c sin (x^2 y^2) = e^x$
Now clearly as $x to -infty ~ , e^x to 0$, so clearly $y to 0$
But answer given is d. Please let me know my mistake.
calculus
For point p(a,b) lying on the curve $2xy^2dx + 2x^2 y dy -
tan(x^2y^2) dx =0 $;
$lim_ato -inftyb =? $
Options are:
a) $ 0$
b) $-1 $
c) $1$
d) does not exist.
Attempt:
If we observe carefully we get:
$d(x^2 y^2) = tan(x^2 y^2) dx$
$implies ln(csin x^2y^2) = x$
$implies c sin (x^2 y^2) = e^x$
Now clearly as $x to -infty ~ , e^x to 0$, so clearly $y to 0$
But answer given is d. Please let me know my mistake.
calculus
calculus
asked 37 mins ago
Abcd
2,6691926
2,6691926
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1 Answer
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We have the following line:
$$c sin (x^2 y^2) = e^x$$
The problem is that $arcsin$ return only a single branch of $sin$, not all of them:
Now, $c sin (x^2 y^2) = e^x$ gives $$sin (x^2 y^2) = frace^xcimplies x^2 y^2=arcsinleft(frace^xcright)colorred+2kpi\implies y=pmfrac1xsqrtarcsinleft(frace^xcright)colorred+2kpi$$So you have more then a single value for $y$ for any fixed $x$ and the answered are as big as we want so the limit won't get rid from them. So the limit is undefined
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
3
down vote
We have the following line:
$$c sin (x^2 y^2) = e^x$$
The problem is that $arcsin$ return only a single branch of $sin$, not all of them:
Now, $c sin (x^2 y^2) = e^x$ gives $$sin (x^2 y^2) = frace^xcimplies x^2 y^2=arcsinleft(frace^xcright)colorred+2kpi\implies y=pmfrac1xsqrtarcsinleft(frace^xcright)colorred+2kpi$$So you have more then a single value for $y$ for any fixed $x$ and the answered are as big as we want so the limit won't get rid from them. So the limit is undefined
add a comment |Â
up vote
3
down vote
We have the following line:
$$c sin (x^2 y^2) = e^x$$
The problem is that $arcsin$ return only a single branch of $sin$, not all of them:
Now, $c sin (x^2 y^2) = e^x$ gives $$sin (x^2 y^2) = frace^xcimplies x^2 y^2=arcsinleft(frace^xcright)colorred+2kpi\implies y=pmfrac1xsqrtarcsinleft(frace^xcright)colorred+2kpi$$So you have more then a single value for $y$ for any fixed $x$ and the answered are as big as we want so the limit won't get rid from them. So the limit is undefined
add a comment |Â
up vote
3
down vote
up vote
3
down vote
We have the following line:
$$c sin (x^2 y^2) = e^x$$
The problem is that $arcsin$ return only a single branch of $sin$, not all of them:
Now, $c sin (x^2 y^2) = e^x$ gives $$sin (x^2 y^2) = frace^xcimplies x^2 y^2=arcsinleft(frace^xcright)colorred+2kpi\implies y=pmfrac1xsqrtarcsinleft(frace^xcright)colorred+2kpi$$So you have more then a single value for $y$ for any fixed $x$ and the answered are as big as we want so the limit won't get rid from them. So the limit is undefined
We have the following line:
$$c sin (x^2 y^2) = e^x$$
The problem is that $arcsin$ return only a single branch of $sin$, not all of them:
Now, $c sin (x^2 y^2) = e^x$ gives $$sin (x^2 y^2) = frace^xcimplies x^2 y^2=arcsinleft(frace^xcright)colorred+2kpi\implies y=pmfrac1xsqrtarcsinleft(frace^xcright)colorred+2kpi$$So you have more then a single value for $y$ for any fixed $x$ and the answered are as big as we want so the limit won't get rid from them. So the limit is undefined
answered 24 mins ago
Holo
4,8352829
4,8352829
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