document.write( "Question 421510: pls. help me solve this problem.. thank you so much.\r
\n" ); document.write( "\n" ); document.write( "verify each of the following identity:\r
\n" ); document.write( "\n" ); document.write( "1. sin ( pi/2 + A) = cosA\r
\n" ); document.write( "\n" ); document.write( "2. sin (A+B) / sin (A-B)=tanA + tanB /tanA-tanB \n" ); document.write( "
Algebra.Com's Answer #294871 by lwsshak3(11628)\"\" \"About 
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1. sin ( pi/2 + A) = cosA
\n" ); document.write( "2. sin (A+B) / sin (A-B)=tanA + tanB /tanA-tanB\r
\n" ); document.write( "\n" ); document.write( ".
\n" ); document.write( "1.sin(pi/2+A)=cosA
\n" ); document.write( "starting with left side
\n" ); document.write( "using sin addition formula and following identities
\n" ); document.write( "cos pi/2=0
\n" ); document.write( "sin pi/2=1
\n" ); document.write( "sin(pi/2+A)=sinpi/2cosA+cospi/2sinA
\n" ); document.write( "=(1)cosA+(0)sinA
\n" ); document.write( "=cosA
\n" ); document.write( "verified: left side=right side
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\n" ); document.write( "\n" ); document.write( "2.sin(A+B)/sin(A-B)=tanA+tanB/tanA-tanB
\n" ); document.write( "starting with right side
\n" ); document.write( "tanA+tanB/tanA-tanB
\n" ); document.write( "=[(sinA/cosA)+(sinB/cosB)]/[(sinA/cosA)-(sinB/cosB)]
\n" ); document.write( "LCD=cosAcosB
\n" ); document.write( "=[(sinAcosB)+(cosAsinB)]/[(sinAcosB)-(cosA/sinB)]
\n" ); document.write( "=sin(A+B)/sin(A-B)
\n" ); document.write( "verified: right side=left side\r
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