document.write( "Question 70001: the rectangular coordinates of a particular point are x=7, y=-24, find the polar coordinates.. \n" ); document.write( "
Algebra.Com's Answer #49854 by bucky(2189)\"\" \"About 
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the rectangular coordinates of a particular point are x=7, y=-24, find the polar coordinates...\r
\n" ); document.write( "\n" ); document.write( "Note that since the value of y is negative and the value of x is positive. This puts
\n" ); document.write( "the point in quadrant IV.\r
\n" ); document.write( "\n" ); document.write( "The magnitude of the radius of is the hypotenuse of a right triangle with legs of length
\n" ); document.write( "7 and 24. Use the Pythagorean theorem to find this hypotenuse (H).\r
\n" ); document.write( "\n" ); document.write( "\"H+=+sqrt%287%5E2+%2B+24%5E2%29\"\r
\n" ); document.write( "\n" ); document.write( "\"H+=+sqrt%2849%2B576%29+=+sqrt%28625%29+=+25\"\r
\n" ); document.write( "\n" ); document.write( "That gives us Magnitude. All we need now is the angle. The ratio of the angle is legs
\n" ); document.write( "of the triangle are:
\n" ); document.write( "\"y%2Fx=%28-24%2F7%29=+-3.428571429\"\r
\n" ); document.write( "\n" ); document.write( "This meets the definition of the tangent of the angle whose opposite side is -24 and whose
\n" ); document.write( "adjacent side is +7. Notice how this falls into quadrant IV = Since this ratio is the
\n" ); document.write( "tangent, by applying arctangent on a calculator, we find that the angle is -73.73979 degrees. \r
\n" ); document.write( "\n" ); document.write( "The polar form can be written in two ways:\r
\n" ); document.write( "\n" ); document.write( " 25/-73.73979\r
\n" ); document.write( "\n" ); document.write( "which means a magnitude of 25 units with an angle found by rotating the magnitude
\n" ); document.write( "clockwise from positive portion of the x-axis by the amount 73.73979 degrees.\r
\n" ); document.write( "\n" ); document.write( "The angle can also be established by rotating (360-73.73979 or 286.26021 degrees)
\n" ); document.write( "counter-clockwise from the positive portion of the x-axis. This would be written as:\r
\n" ); document.write( "\n" ); document.write( " 25/286.26021\r
\n" ); document.write( "\n" ); document.write( "I hope this helps you to understand the relationship between the Cartesian and polar representations
\n" ); document.write( "of points and specifically how to change from rectangular to polar form.\r
\n" ); document.write( "\n" ); document.write( "You may also find it helpful to make a rough sketch of the rectangular point (7,-24) and
\n" ); document.write( "draw the magnitude (radius) from the origin to this point. Measure out 7 on the positive
\n" ); document.write( "x-axis and the vertical distance from the point (7,0) to the point (7, -24). This will
\n" ); document.write( "help you to see the right triangle (0,0) to (7,0), from (7,0) to (7, -24), and then from
\n" ); document.write( "(7, -24) to (0,0). The two points (7, -24) to (0,0) are the ends of the radius and the
\n" ); document.write( "Magnitude of this line can also be found using the formula for the distance between two points.
\n" ); document.write( "the tangent of the angle is the ratio of the length of the line (7,0) to (7, -24) over
\n" ); document.write( "the length of the line from (0,0) to (7,0). Such a rough sketch will help you to visualize
\n" ); document.write( "the problem.\r
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