document.write( "Question 973137: Find the magnitude and direction angle θ of the following vectors. Round the magnitude to the nearest tenth, and round the direction angle to the nearest degree, if rounding is necessary.\r
\n" ); document.write( "\n" ); document.write( "v = (-5, -2)
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Algebra.Com's Answer #595511 by Theo(13342)\"\" \"About 
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if this vector starts at the origin, then you will get:\r
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\n" ); document.write( "\n" ); document.write( "p1 = (0,0)
\n" ); document.write( "p2 = (-5,-2)\r
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\n" ); document.write( "\n" ); document.write( "the x-coordinate of p2 is -5
\n" ); document.write( "the y-coordinate of p2 is -2\r
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\n" ); document.write( "\n" ); document.write( "those coordinates form a right triangle with the origin.\r
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\n" ); document.write( "\n" ); document.write( "the tangent of the angle of that triangle would be -2/-5.\r
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\n" ); document.write( "\n" ); document.write( "tan^-1(2/5) = 21.80140949 degrees.
\n" ); document.write( "that's the reference angle of the triangle in quaedrant 3.
\n" ); document.write( "the angle in quadrant 3 is 180 + 21.80140949 = 201.80140949 degrees.\r
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\n" ); document.write( "\n" ); document.write( "that's the direction.\r
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\n" ); document.write( "\n" ); document.write( "the magnitude is sqrt((-2)^2 + (-5)^2) = sqrt(4+25) = sqrt(29).\r
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\n" ); document.write( "\n" ); document.write( "the direction in quadrant 3 is generally in a south west direction.\r
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\n" ); document.write( "\n" ); document.write( "since the reference angle is only 21 degrees, it's closer to west than south.\r
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\n" ); document.write( "\n" ); document.write( "halfway south and halfway west would be an angle of 180 + 45 = 225 degrees.\r
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