document.write( "Question 169035: What is the exact value of this expression. sec^2 50°- tan^2 50° \n" ); document.write( "

Algebra.Com's Answer #124663 by nerdybill(7384) $\"\"$ $\"About$

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One of the trigonometric identity is:
\n" ); document.write( "1+tan^2 u = sec^2 u
\n" ); document.write( ".
\n" ); document.write( "Here is a site w/trig identities:
\n" ); document.write( "http://www.sosmath.com/trig/Trig5/trig5/trig5.html
\n" ); document.write( ".
\n" ); document.write( "so, if we started with:
\n" ); document.write( "1+tan^2 u = sec^2 u
\n" ); document.write( "subtracting tan^2 u from both sides:
\n" ); document.write( "1 = sec^2 u - tan^2 u
\n" ); document.write( ".
\n" ); document.write( "Therefore:
\n" ); document.write( "sec^2 50°- tan^2 50° = 1 \n" ); document.write( "

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