document.write( "Question 799078: tan(sin^-1 3/4-cox^-1 1/7) \n" ); document.write( "
Algebra.Com's Answer #482514 by DrBeeee(684)\"\" \"About 
You can put this solution on YOUR website!
My solution may not be elegant, but I think it's right.
\n" ); document.write( "Given expression
\n" ); document.write( "(1) tan(arcsin(3/4) - arccos(1/7))
\n" ); document.write( "Let
\n" ); document.write( "(2) a = arcsin(3/4), then
\n" ); document.write( "(3) sin(a) = 3/4 and using
\n" ); document.write( "(4) \"sin%5E2%28a%29+%2B+cos%5E2%28a%29+=+1\" we get
\n" ); document.write( "(5) \"cos%5E2%28a%29+=+1+-+%283%2F4%29%5E2\" or
\n" ); document.write( "(6) \"cos%28a%29+=+sqrt%287%29%2F4\"
\n" ); document.write( "Now let
\n" ); document.write( "(7) b = arccos(1/7), then
\n" ); document.write( "(8) cos(b) = 1/7 and using
\n" ); document.write( "(9) \"sin%5E2%28b%29+%2B+cos%5E2%28b%29+=+1\" we get
\n" ); document.write( "(10)\"+sin%5E2%28b%29+%2B+%281%2F7%29%5E2+=+1\" or
\n" ); document.write( "(11) \"sin%5E2%28b%29+=+1+-+%281%2F7%29%5E2\" or
\n" ); document.write( "(12)\"+sin%28b%29+=+%284%2F7%29%2Asqrt%283%29\"
\n" ); document.write( "Now a biggy!
\n" ); document.write( "Use the following identities
\n" ); document.write( "(13) \"tan%28a-b%29+=+%28sin%28a-b%29%29%2F%28cos%28a-b%29%29\"
\n" ); document.write( "(14) sin(a-b) = sin(a)cos(b) - cos(a)sin(b)
\n" ); document.write( "(15) cos(a-b) = cos(a)cos(b) + sin(a)sin(b)
\n" ); document.write( "There may be a more direct way to get (13), but I dont have an extensive table of trig identities in my brain. These are the only ones I remember.
\n" ); document.write( "Anyway substitute (3), (6), (8), and (12) into (14) and (15) to get
\n" ); document.write( "(16) and
\n" ); document.write( "(17)
\n" ); document.write( "Now put (16) and (17) into (13) to get the solution to the problem. Note that all four terms have the common denominator, 28. Since it is in a ratio, it cancels out to give us
\n" ); document.write( "(18)\r
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