Finding the image of $y=2x+5$ under the transformation $w=(1+i)z-2$
Clash Royale CLAN TAG#URR8PPP
up vote
0
down vote
favorite
I am trying to find the image of the line $y=2x+5$ under the transformation $w=(1+i)z-2$.
I'm uncertain of how to proceed in questions that do not involve the mapping $w=frac1z$. I thought that if I could rewrite the mapping as $w=sqrt2e^fracpi4iz-2$, this would indicate that the straight line is rotated anticlockwise about the origin by an angle of $fracpi4$, is dilated by $sqrt2$ and translated by 2 units to the right, but I am not confident in these statements.
Is there a general method on how to solve this question? A hint would be very helpful :)
complex-analysis functions
add a comment |Â
up vote
0
down vote
favorite
I am trying to find the image of the line $y=2x+5$ under the transformation $w=(1+i)z-2$.
I'm uncertain of how to proceed in questions that do not involve the mapping $w=frac1z$. I thought that if I could rewrite the mapping as $w=sqrt2e^fracpi4iz-2$, this would indicate that the straight line is rotated anticlockwise about the origin by an angle of $fracpi4$, is dilated by $sqrt2$ and translated by 2 units to the right, but I am not confident in these statements.
Is there a general method on how to solve this question? A hint would be very helpful :)
complex-analysis functions
add a comment |Â
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I am trying to find the image of the line $y=2x+5$ under the transformation $w=(1+i)z-2$.
I'm uncertain of how to proceed in questions that do not involve the mapping $w=frac1z$. I thought that if I could rewrite the mapping as $w=sqrt2e^fracpi4iz-2$, this would indicate that the straight line is rotated anticlockwise about the origin by an angle of $fracpi4$, is dilated by $sqrt2$ and translated by 2 units to the right, but I am not confident in these statements.
Is there a general method on how to solve this question? A hint would be very helpful :)
complex-analysis functions
I am trying to find the image of the line $y=2x+5$ under the transformation $w=(1+i)z-2$.
I'm uncertain of how to proceed in questions that do not involve the mapping $w=frac1z$. I thought that if I could rewrite the mapping as $w=sqrt2e^fracpi4iz-2$, this would indicate that the straight line is rotated anticlockwise about the origin by an angle of $fracpi4$, is dilated by $sqrt2$ and translated by 2 units to the right, but I am not confident in these statements.
Is there a general method on how to solve this question? A hint would be very helpful :)
complex-analysis functions
asked Aug 1 at 9:36
Bell
560112
560112
add a comment |Â
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
2
down vote
accepted
You're overcomplicating it.
Set $z=t+(2t+5)i$. Plug into your transformation. Evaluate. You get a parametric equation for the image of the line.
Can this method be extended to other transformations? Or only in the case where $w$ is linear?
– Bell
Aug 1 at 10:13
@Bell: It will always give you a parametric equation for whatever the image is, but the shape of the parametric equation is not necessarily nice when your $w$ isn't.
– Henning Makholm
Aug 1 at 10:16
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
2
down vote
accepted
You're overcomplicating it.
Set $z=t+(2t+5)i$. Plug into your transformation. Evaluate. You get a parametric equation for the image of the line.
Can this method be extended to other transformations? Or only in the case where $w$ is linear?
– Bell
Aug 1 at 10:13
@Bell: It will always give you a parametric equation for whatever the image is, but the shape of the parametric equation is not necessarily nice when your $w$ isn't.
– Henning Makholm
Aug 1 at 10:16
add a comment |Â
up vote
2
down vote
accepted
You're overcomplicating it.
Set $z=t+(2t+5)i$. Plug into your transformation. Evaluate. You get a parametric equation for the image of the line.
Can this method be extended to other transformations? Or only in the case where $w$ is linear?
– Bell
Aug 1 at 10:13
@Bell: It will always give you a parametric equation for whatever the image is, but the shape of the parametric equation is not necessarily nice when your $w$ isn't.
– Henning Makholm
Aug 1 at 10:16
add a comment |Â
up vote
2
down vote
accepted
up vote
2
down vote
accepted
You're overcomplicating it.
Set $z=t+(2t+5)i$. Plug into your transformation. Evaluate. You get a parametric equation for the image of the line.
You're overcomplicating it.
Set $z=t+(2t+5)i$. Plug into your transformation. Evaluate. You get a parametric equation for the image of the line.
answered Aug 1 at 9:40
Henning Makholm
225k16290516
225k16290516
Can this method be extended to other transformations? Or only in the case where $w$ is linear?
– Bell
Aug 1 at 10:13
@Bell: It will always give you a parametric equation for whatever the image is, but the shape of the parametric equation is not necessarily nice when your $w$ isn't.
– Henning Makholm
Aug 1 at 10:16
add a comment |Â
Can this method be extended to other transformations? Or only in the case where $w$ is linear?
– Bell
Aug 1 at 10:13
@Bell: It will always give you a parametric equation for whatever the image is, but the shape of the parametric equation is not necessarily nice when your $w$ isn't.
– Henning Makholm
Aug 1 at 10:16
Can this method be extended to other transformations? Or only in the case where $w$ is linear?
– Bell
Aug 1 at 10:13
Can this method be extended to other transformations? Or only in the case where $w$ is linear?
– Bell
Aug 1 at 10:13
@Bell: It will always give you a parametric equation for whatever the image is, but the shape of the parametric equation is not necessarily nice when your $w$ isn't.
– Henning Makholm
Aug 1 at 10:16
@Bell: It will always give you a parametric equation for whatever the image is, but the shape of the parametric equation is not necessarily nice when your $w$ isn't.
– Henning Makholm
Aug 1 at 10:16
add a comment |Â
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2868886%2ffinding-the-image-of-y-2x5-under-the-transformation-w-1iz-2%23new-answer', 'question_page');
);
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password