document.write( "Question 735822: when finding the values of inverse trigonometric functions, how do you get from.. Cos-1 (-0.5) =x cos x = -0.5 and 0_< x _< pi to Cos -1 (-0.5) = 2 pi over 3? \n" ); document.write( "

Algebra.Com's Answer #449587 by lwsshak3(11628) $\"\"$ $\"About$

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when finding the values of inverse trigonometric functions, how do you get from.. Cos-1 (-0.5) =x cos x = -0.5 and 0_< x _< pi to Cos -1 (-0.5) = 2 pi over 3?
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\n" ); document.write( "Cos -1 (-0.5) = 2 pi over 3
\n" ); document.write( "Inverse cos(-0.5)=2π/3
\n" ); document.write( "This reads: (2π/3 is an angle between 0 and π whose cos is= (-0.5)
\n" ); document.write( "This also means the angle must be in quadrant I or quadrant II.
\n" ); document.write( "cos>0 in quadrant I and cos<0 in quadrant II
\n" ); document.write( "So the angle must be in quadrant II since the given cos inverse =(-0.5)<0.
\n" ); document.write( "If given cos inverse was (0.5)>0, the angle would be in quadrant I=π/3 instead of 2π/3 in quadrant II
\n" ); document.write( "By definition, the cos inverse domain is restricted to [0,π] \n" ); document.write( "

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