What is the shortest path from (-2,0) to (2,0) that avoids the interior but not the circumference of a circle...











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What is the shortest path from (-2,0) to (2,0) that avoids the interior but not the circumference of a circle with a radius 1 centered at the origin?



I am getting the answer $$2sqrt{3}$$ even though the answer is $$2sqrt{3} + π/3$$



I don't understand why, can anyone explain why that is?
Thanks










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  • 1




    Maybe we can explain it, if you show us how you got your answer.
    – saulspatz
    Nov 24 at 20:51










  • I was thinking I should make a 1,2,sqrt3 triangle and because sqrt 3 is the missing side, and I just multiplied the answer by two. As to the actual answer, my answer key provided me with the number without any explanation.
    – BLoby Blob
    Nov 24 at 20:54












  • The problem with your solution is that the $sqrt{3}$ side of the triangle will pass through the interior of the circle won't it? By the way, this has nothing to do with algebraic geometry, which is a very advanced subject. Are you taking calculus?
    – saulspatz
    Nov 24 at 20:57










  • I'll change the tag then. I'm taking an algebra 2 trig course
    – BLoby Blob
    Nov 24 at 21:13















up vote
0
down vote

favorite












What is the shortest path from (-2,0) to (2,0) that avoids the interior but not the circumference of a circle with a radius 1 centered at the origin?



I am getting the answer $$2sqrt{3}$$ even though the answer is $$2sqrt{3} + π/3$$



I don't understand why, can anyone explain why that is?
Thanks










share|cite|improve this question




















  • 1




    Maybe we can explain it, if you show us how you got your answer.
    – saulspatz
    Nov 24 at 20:51










  • I was thinking I should make a 1,2,sqrt3 triangle and because sqrt 3 is the missing side, and I just multiplied the answer by two. As to the actual answer, my answer key provided me with the number without any explanation.
    – BLoby Blob
    Nov 24 at 20:54












  • The problem with your solution is that the $sqrt{3}$ side of the triangle will pass through the interior of the circle won't it? By the way, this has nothing to do with algebraic geometry, which is a very advanced subject. Are you taking calculus?
    – saulspatz
    Nov 24 at 20:57










  • I'll change the tag then. I'm taking an algebra 2 trig course
    – BLoby Blob
    Nov 24 at 21:13













up vote
0
down vote

favorite









up vote
0
down vote

favorite











What is the shortest path from (-2,0) to (2,0) that avoids the interior but not the circumference of a circle with a radius 1 centered at the origin?



I am getting the answer $$2sqrt{3}$$ even though the answer is $$2sqrt{3} + π/3$$



I don't understand why, can anyone explain why that is?
Thanks










share|cite|improve this question















What is the shortest path from (-2,0) to (2,0) that avoids the interior but not the circumference of a circle with a radius 1 centered at the origin?



I am getting the answer $$2sqrt{3}$$ even though the answer is $$2sqrt{3} + π/3$$



I don't understand why, can anyone explain why that is?
Thanks







geometry






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edited Nov 24 at 21:14

























asked Nov 24 at 20:48









BLoby Blob

3616




3616








  • 1




    Maybe we can explain it, if you show us how you got your answer.
    – saulspatz
    Nov 24 at 20:51










  • I was thinking I should make a 1,2,sqrt3 triangle and because sqrt 3 is the missing side, and I just multiplied the answer by two. As to the actual answer, my answer key provided me with the number without any explanation.
    – BLoby Blob
    Nov 24 at 20:54












  • The problem with your solution is that the $sqrt{3}$ side of the triangle will pass through the interior of the circle won't it? By the way, this has nothing to do with algebraic geometry, which is a very advanced subject. Are you taking calculus?
    – saulspatz
    Nov 24 at 20:57










  • I'll change the tag then. I'm taking an algebra 2 trig course
    – BLoby Blob
    Nov 24 at 21:13














  • 1




    Maybe we can explain it, if you show us how you got your answer.
    – saulspatz
    Nov 24 at 20:51










  • I was thinking I should make a 1,2,sqrt3 triangle and because sqrt 3 is the missing side, and I just multiplied the answer by two. As to the actual answer, my answer key provided me with the number without any explanation.
    – BLoby Blob
    Nov 24 at 20:54












  • The problem with your solution is that the $sqrt{3}$ side of the triangle will pass through the interior of the circle won't it? By the way, this has nothing to do with algebraic geometry, which is a very advanced subject. Are you taking calculus?
    – saulspatz
    Nov 24 at 20:57










  • I'll change the tag then. I'm taking an algebra 2 trig course
    – BLoby Blob
    Nov 24 at 21:13








1




1




Maybe we can explain it, if you show us how you got your answer.
– saulspatz
Nov 24 at 20:51




Maybe we can explain it, if you show us how you got your answer.
– saulspatz
Nov 24 at 20:51












I was thinking I should make a 1,2,sqrt3 triangle and because sqrt 3 is the missing side, and I just multiplied the answer by two. As to the actual answer, my answer key provided me with the number without any explanation.
– BLoby Blob
Nov 24 at 20:54






I was thinking I should make a 1,2,sqrt3 triangle and because sqrt 3 is the missing side, and I just multiplied the answer by two. As to the actual answer, my answer key provided me with the number without any explanation.
– BLoby Blob
Nov 24 at 20:54














The problem with your solution is that the $sqrt{3}$ side of the triangle will pass through the interior of the circle won't it? By the way, this has nothing to do with algebraic geometry, which is a very advanced subject. Are you taking calculus?
– saulspatz
Nov 24 at 20:57




The problem with your solution is that the $sqrt{3}$ side of the triangle will pass through the interior of the circle won't it? By the way, this has nothing to do with algebraic geometry, which is a very advanced subject. Are you taking calculus?
– saulspatz
Nov 24 at 20:57












I'll change the tag then. I'm taking an algebra 2 trig course
– BLoby Blob
Nov 24 at 21:13




I'll change the tag then. I'm taking an algebra 2 trig course
– BLoby Blob
Nov 24 at 21:13










1 Answer
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up vote
2
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accepted










I misunderstood what you had done, sorry. You have constructed the tangent from $(-2,0)$ to the circle, and computed its length as $sqrt{3}$ and done the same thing on the other side. The problem is that these two segments together do no give a path from $(-2,0)$ to $(2,0)$. You have to add in the arc of the circle joining the points of tangency.



You will have to compute the central angle subtending this arc. To do this, you should compute the angles of the triangle you constructed, using trigonometry. Intuitively, this is surely the shortest path, though the above discussion by no means constitutes a proof. I suspect you are not expected to prove it, though.



In fact, if you'e taking algebra/trig I feel sure you don't have to give a proof.






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    1 Answer
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    up vote
    2
    down vote



    accepted










    I misunderstood what you had done, sorry. You have constructed the tangent from $(-2,0)$ to the circle, and computed its length as $sqrt{3}$ and done the same thing on the other side. The problem is that these two segments together do no give a path from $(-2,0)$ to $(2,0)$. You have to add in the arc of the circle joining the points of tangency.



    You will have to compute the central angle subtending this arc. To do this, you should compute the angles of the triangle you constructed, using trigonometry. Intuitively, this is surely the shortest path, though the above discussion by no means constitutes a proof. I suspect you are not expected to prove it, though.



    In fact, if you'e taking algebra/trig I feel sure you don't have to give a proof.






    share|cite|improve this answer

























      up vote
      2
      down vote



      accepted










      I misunderstood what you had done, sorry. You have constructed the tangent from $(-2,0)$ to the circle, and computed its length as $sqrt{3}$ and done the same thing on the other side. The problem is that these two segments together do no give a path from $(-2,0)$ to $(2,0)$. You have to add in the arc of the circle joining the points of tangency.



      You will have to compute the central angle subtending this arc. To do this, you should compute the angles of the triangle you constructed, using trigonometry. Intuitively, this is surely the shortest path, though the above discussion by no means constitutes a proof. I suspect you are not expected to prove it, though.



      In fact, if you'e taking algebra/trig I feel sure you don't have to give a proof.






      share|cite|improve this answer























        up vote
        2
        down vote



        accepted







        up vote
        2
        down vote



        accepted






        I misunderstood what you had done, sorry. You have constructed the tangent from $(-2,0)$ to the circle, and computed its length as $sqrt{3}$ and done the same thing on the other side. The problem is that these two segments together do no give a path from $(-2,0)$ to $(2,0)$. You have to add in the arc of the circle joining the points of tangency.



        You will have to compute the central angle subtending this arc. To do this, you should compute the angles of the triangle you constructed, using trigonometry. Intuitively, this is surely the shortest path, though the above discussion by no means constitutes a proof. I suspect you are not expected to prove it, though.



        In fact, if you'e taking algebra/trig I feel sure you don't have to give a proof.






        share|cite|improve this answer












        I misunderstood what you had done, sorry. You have constructed the tangent from $(-2,0)$ to the circle, and computed its length as $sqrt{3}$ and done the same thing on the other side. The problem is that these two segments together do no give a path from $(-2,0)$ to $(2,0)$. You have to add in the arc of the circle joining the points of tangency.



        You will have to compute the central angle subtending this arc. To do this, you should compute the angles of the triangle you constructed, using trigonometry. Intuitively, this is surely the shortest path, though the above discussion by no means constitutes a proof. I suspect you are not expected to prove it, though.



        In fact, if you'e taking algebra/trig I feel sure you don't have to give a proof.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 24 at 21:15









        saulspatz

        13.3k21327




        13.3k21327






























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