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Trignometry
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ravi tej
Cool goIITian

Joined: 29 May 2007
Posts: 61
4 Jun 2007 22:52:30 IST
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the ans is cot
and the required tan is undefined for sin
=1/2 and sin
=0
and the required tan is undefined for sin
=1/2 and sin
=0if u want to know how/?
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4 Jun 2007 23:09:47 IST
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from given eqn , sum of roots
tan
= sin 2
tan
= sin 2
sum of product of 2 roots at a time =
tan
1tan
2 = cos 2
tan
1tan
2 = cos 2
tan
1 tan
2 tan
3 = cos
tan
1 tan
2 tan
3 tan
4 = -sin
1 tan
2 tan
3 tan
4 = -sin
tan (
1 +
2) = (tan
1+ tan
2 )/(1 - tan
1 tan
2)
1 +
2) = (tan
1+ tan
2 )/(1 - tan
1 tan
2)use same formula 2 add tan (
3 +
4), again use d same & simplify,
3 +
4), again use d same & simplify, tan { (
1 +
2) + (
3 +
4) } = (
tan
-
tan
1tan
2tan
3) / (1- tan
1tan
2tan
3tan
4 -
tan
1tan
2)
1 +
2) + (
3 +
4) } = (
tan
-
tan
1tan
2tan
3) / (1- tan
1tan
2tan
3tan
4 -
tan
1tan
2) = (sin2
- cos
) /(1+sin
-cos 2
)
- cos
) /(1+sin
-cos 2
) = (2sin
cos
- cos
)/(1 +sin
-(1 - 2sin2
))
cos
- cos
)/(1 +sin
-(1 - 2sin2
)) =cot
4 Jun 2007 23:10:39 IST
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yeah sure
if you know this,then it is well & good
else learn it now
tan(x+y+z+..........)=(t1-t3+t5-...........................)/((t0-t2+t4-.............)
where tn is sum of tangents taken n at a timme
for ex. in tan(x+y+z),t2 is tanxtany+tanytanz+tanztanx
and t0 is 1
hence tan (
1+
2+
3+
4) is t1-t3/1-t2+t4
1+
2+
3+
4) is t1-t3/1-t2+t4since t1 is sin2x and t2 is cos2x and t3 is cosx and t4
is -sin2x by simple trasformations we get the required result
5 Jun 2007 07:49:49 IST
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Good work irlmarks and lazycol.
Remember :
tan(x1+x2+x3+......) = (T1 - T3 + T5 ........) / (1 - T2 + T4 ......)
where , Tr is the sum of tangents taken r at a time.
So, tan(
1+
2+
3+
4) = (T1 - T3) / (1 - T2 + T4)= (sin2
- cos
) / (1- cos 2
- sin
)
tan(
1+
2+
3+
4) = (2sin
cos
- cos
) / (2sin2
- sin
)
tan(
1+
2+
3+
4) = (cos
)(2sin
-1) / (sin
)(2sin
- 1) = cot
Since we are cancelling 2sin
-1 , 2sin
-1
0.
Also for
=0 , cot
would be undefined.
Remember :
tan(x1+x2+x3+......) = (T1 - T3 + T5 ........) / (1 - T2 + T4 ......)
where , Tr is the sum of tangents taken r at a time.
So, tan(
1+
2+
3+
4) = (T1 - T3) / (1 - T2 + T4)= (sin2
- cos
) / (1- cos 2
- sin
)tan(
1+
2+
3+
4) = (2sin
cos
- cos
) / (2sin2
- sin
)tan(
1+
2+
3+
4) = (cos
)(2sin
-1) / (sin
)(2sin
- 1) = cot
Since we are cancelling 2sin
-1 , 2sin
-1
0.Also for
=0 , cot
would be undefined.











