document.write( "Question 659149: I think this is trignonmetry i'm not completely sure. Could Someone help me by explaining this and how to answer it.
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document.write( "(a)Use a trigonometric identity and then algebra to solve the equation sin^2 x = cos x, 0 ≤ x ≤ 2π. Give all your solutions in radians.
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document.write( "(b)On the same set of axes draw the two graphs y = sin^2x and y = cos x for the domain [0,2π ] . Show on your graph where your solutions to part (a) are. \n" );
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Algebra.Com's Answer #410684 by lwsshak3(11628)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "(a)Use a trigonometric identity and then algebra to solve the equation sin^2 x = cos x, 0 ≤ x ≤ 2π. Give all your solutions in radians. \n" ); document.write( ".. \n" ); document.write( "sin^2x=cosx \n" ); document.write( "Identity:sin^2x+cos^2x=1 \n" ); document.write( "sin^2x=1-cos^2x \n" ); document.write( ".. \n" ); document.write( "1-cos^2x=cosx \n" ); document.write( "cos^2x+cosx-1=0 \n" ); document.write( "let u=cosx \n" ); document.write( "u^2+u-1=0 \n" ); document.write( "solve for u by following quadratic formula: \n" ); document.write( " \n" ); document.write( "a=1, b=1, c=-1 \n" ); document.write( "ans \n" ); document.write( "u≈-1.62 (reject, not in domain) \n" ); document.write( "or \n" ); document.write( "u≈.618 \n" ); document.write( "cosx=.618 \n" ); document.write( "from calculator: \n" ); document.write( "x=.905 and 5.378 radians (in quadrants I and IV where cos>0) \n" ); document.write( ".. \n" ); document.write( "b)On the same set of axes draw the two graphs y = sin^2x and y = cos x for the domain [0,2π ] . Show on your graph where your solutions to part (a) are. \n" ); document.write( ".. \n" ); document.write( "I don't have the means to draw graphs for you, but I will provide the coordinates with which you can draw the graphs yourself. \n" ); document.write( ".. \n" ); document.write( "For cosx for 1 period (0-2π) \n" ); document.write( "(0,1), (π/2,0), (π,-1), (3π/2,0), (2π,1) \n" ); document.write( ".. \n" ); document.write( "For sin^2x for 1 period \n" ); document.write( "(0,0), (π/2,1), (π,0), (3π/2,1), (2π/0) \n" ); document.write( ".. \n" ); document.write( "If you draw these two curves correctly, you will find that they intersect at coordinates (0.905,0.618) and (5.378,0.618) \n" ); document.write( " \n" ); document.write( " |