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	Archimedes Burning Mirror		2012-07-17
		Frakeetta pose la question : Archimedes Burning Mirror There is a story about Archimedes that he used a “burning mirror” in the shape of a paraboloid of revolution to set fire to enemy ships in the harbor. What would be the equation of the parabola that one would rotate to form the appropriate paraboloid if it were to be designed to set fire to a ship 100m from the mirror? How large would the burning mirror need to be? What is the likelihood that this story is true? Robert Dawson lui répond.
	A periscope		2009-10-05
		likhitha pose la question : In a periscope, MIRRORS ARE PLACED PARALLELLY.Then why they do not form multiple images Robert Dawson and Chris Fisher lui répond.
	Two mirrors		2007-10-24
		Peter pose la question : The reflecting surfaces of two intersecting flat mirrors are at an angle θ (0° < θ < 90°). For a light ray that strikes the horizontal mirror, show that the emerging ray will intersect the incident ray at an angle β = 180° – 2θ. Stephen La Rocque lui répond.
	who am i?		2007-08-08
		Phillip pose la question : if you hold a mirror horizontally across my middle, i look the same in the mirror.if you hold a mirror between my second and third digits,i look the same in the mirror if you turn me upside down, i look the same. what 6 four-digit numbers could i be? Penny Nom lui répond.
	Looking in the mirror		2007-06-13
		annafe pose la question : why do you think that when you look at the mirror your face is just the same as what it is,while when you read messages on the mirror,it is in inverse? Stephen La Rocque lui répond.
	A parabolic mirror		2005-05-24
		Nathan pose la question : i am trying to find the equation for a mirror for a laser experiment. the mirror is parabolic but my question is how do you find the equation when you know only the focus and the diameter the mirror diameter is 520 mm and the focus is at 1024 mm. would you just use the measurements in the equation instead of "nice numbers" or what. Penny Nom lui répond.
	Lines of symmetry		2002-04-22
		Cindie pose la question : How many lines of symmetry do the following figures contain? trapezoid: rhombus: hexagon: pentagon: Walter Whiteley lui répond.
	Parabolic mirrors		1999-11-07
		Andy White pose la question : I am working on a project concerning parabolic mirrors. I need to create a mirror to focus sunlight on a focal point, but I don't know how to do it. Is there some equation that tells where a focal point will be in relation to a parabola? What is a directrix? Penny Nom lui répond.
	Satellite dishes		1999-02-10
		Katherine Shaw pose la question : I have read your information on 'Why are satellite dishes parabolic", and I know the reciever should be placed at the focus of the parabola. Could you test this with lights beams and a parabolic mirror, or would light beams behave differently. Thanks. Jack LeSage and Harley Weston lui répond.
	Parabolic Mirrors		1997-01-28
		Megan Wennberg pose la question : Consider a ray of light that passes through a chord of a parabola (the chord is above the focus and parallel to the directrix), hits the parabola at a point (x,y) and is reflected through the focus. If d1 is the distance from the chord to the point of incidence (x,y) and d2 is the distance from (x,y) to the focus, can you prove that the sum of the distances d1+d2 is constant, independent of the particular point of incidence. Penny Nom lui répond.

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