physics chemistry maths science forums
become expert I help I sign up I login
refer a friend - earn nickels!!   
 advanced
 
Home
Ask & Discuss Questions
Study Material
Experts Zone
Hang Out!

Ask & Discuss Questions with Community & Experts

Moderation Team
 90 chars left    advanced
Ask iit jee aieee pet cbse icse state board experts Expert Question: i need it to be solved immediately please.......................
Forum Index -> Trignometry like the article? email it to a friend.  
Author Message
road (0)

New kid on the Block

Olaaa!! Perrrfect answer. 0  [0 rates]

road's Avatar

total posts: 11    
offline Offline
 f(x) = tanx - tanx tanx tanx +tanx tanx tanx tanx tanx+..................+ infinity
0 less than  x less than 45 degrees then
 
 
[0 ][/4 ]   f(x) dx =
    
sunip_the_mini_mastermind (133)

Scorching goIITian

Olaaa!! Perrrfect answer. 19  [38 rates]

sunip_the_mini_mastermind's Avatar

total posts: 208    
offline Offline
is it 1/4
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
road (0)

New kid on the Block

Olaaa!! Perrrfect answer. 0  [0 rates]

road's Avatar

total posts: 11    
offline Offline
tell me hw to solve this problem
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
road (0)

New kid on the Block

Olaaa!! Perrrfect answer. 0  [0 rates]

road's Avatar

total posts: 11    
offline Offline
sunip tell me hw did u solve the sum
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
dream (571)

Blazing goIITian

Olaaa!! Perrrfect answer. 89  [152 rates]

dream's Avatar

total posts: 495    
offline Offline
i think the answer should be
-1/4
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
sunip_the_mini_mastermind (133)

Scorching goIITian

Olaaa!! Perrrfect answer. 19  [38 rates]

sunip_the_mini_mastermind's Avatar

total posts: 208    
offline Offline
it is infinite g.p. with common difference -tan2x.
now sum of the g.p. will be tanx/1+tan2x
which is equal to sinxcosx....now u can integrate it easily

 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
road (0)

New kid on the Block

Olaaa!! Perrrfect answer. 0  [0 rates]

road's Avatar

total posts: 11    
offline Offline
sunip can u explain it more briefly
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
ashish_banga (937)

Blazing goIITian

Olaaa!! Perrrfect answer. 147  bad job dude!! I dont approve of this answer! 1  [250 rates]

ashish_banga's Avatar

total posts: 1305    
offline Offline
i am getting -1/4
f(x) =  sinx cosx
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
road (0)

New kid on the Block

Olaaa!! Perrrfect answer. 0  [0 rates]

road's Avatar

total posts: 11    
offline Offline
sunip tell me hw did u find the sum of gp
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
dream (571)

Blazing goIITian

Olaaa!! Perrrfect answer. 89  [152 rates]

dream's Avatar

total posts: 495    
offline Offline
the sum of GP can be found by using the summation formula of infinite terms
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
sunip_the_mini_mastermind (133)

Scorching goIITian

Olaaa!! Perrrfect answer. 19  [38 rates]

sunip_the_mini_mastermind's Avatar

total posts: 208    
offline Offline
its the sum of an infinite g.p.the formula is as follows..
s=a/1-r;a=first term ,r=common difference ,|r|<1
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
road (0)

New kid on the Block

Olaaa!! Perrrfect answer. 0  [0 rates]

road's Avatar

total posts: 11    
offline Offline
even iam getting -1/4 but the right ans is 1/4 what to do sunip
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
aggmegha90 (63)

Blazing goIITian

Olaaa!! Perrrfect answer. 9  [18 rates]

aggmegha90's Avatar

total posts: 361    
offline Offline
hey ans is 1/4. ......... i think u all r doing mistake in integration of sin, it is -cos
rate me please
 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
edison (4435)

Forum Expert Blazing goIITian

Olaaa!! Perrrfect answer. 783  [1043 rates]

edison's Avatar

total posts: 2269    
offline Offline
Q) f(x) = tanx - tanx tanx tanx +tanx tanx tanx tanx tanx+..................+ infinity
0 less than  x less than 45 degrees then
 
 
[0 ][/4 ]   f(x) dx = ?
 
Sol) Let y  =f(x)  = tanx - tanx tanx tanx +tanx tanx tanx tanx tanx+...............
 
Thus y = tanx -tan2 x ( tanx - tanx tanx tanx +tanx tanx tanx tanx tanx+....)
 
or y = tanx - y tan2 x
 
or y +  y tan2 x = tanx
 
or y = tanx / (1 + tan2 x)
 
or y = sinx cosx = (sin2x)/2
 
Thus, I =  [0 ][/4 ]   f(x) dx
 
or I  =[0 ][/4 ]   y dx
 
or I = [0 ][/4 ]   sin2x / 2 dx
 
or I = -(1/4)(cos/2 - cos0) = 1/4

The most incomprehensible thing about the world is that it is

at all comprehensible.
 this reply: 5 points  (with Olaaa!! Perrrfect answer.   in 1 votes )   [?]
 
You have to be logged on to rate
  
 
Forum Index -> Trignometry
Go to: