Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing

This Question is Closed

AadarshBest ResponseYou've already chosen the best response.2
Solve: [1/(sin 45 sin 46)] + [1/(sin 47 sin 48)] + ........................+ [1(sin 133 sin 134)]
 2 years ago

Mani_JhaBest ResponseYou've already chosen the best response.0
The general term of the series is: \[t(n)=1/\sin x \sin (x+1)\] Now expand sin(x+1) using sin(A+B). Simplify, and you'll get a really simple general term/
 2 years ago

SarkarBest ResponseYou've already chosen the best response.1
i think mani's approach is good!!!!
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
So, we get dw:1334419282831:dw ?
 2 years ago

Mani_JhaBest ResponseYou've already chosen the best response.0
Use (sinx)^2=1cos2x/2 sinxcosx=sin2x/2 Where did sin1 and cos1 go, sarkar?
 2 years ago

Mani_JhaBest ResponseYou've already chosen the best response.0
Actually, sin1=1.17. Yes, aadarsh. You sure you got that general term, Aadarsh?
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
Can u say the detailed steps @Mani_Jha bhai and @Sarkar bhai? using all the steps?
 2 years ago

Mani_JhaBest ResponseYou've already chosen the best response.0
Uh oh, I am not getting a simplified general term using that. Let me think on this.
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
Sure. Try to post it as soon as possible.
 2 years ago

SarkarBest ResponseYou've already chosen the best response.1
note=everyone who have answered this Q is of level 30 and above....lol
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
I think most of them have left this question. i asked to my teacher, she couldn't answer it.
 2 years ago

RecursingBest ResponseYou've already chosen the best response.0
http://www.wolframalpha.com/input/?i=sum_%28k%3D45%29%5E133+1%2F%28sin%28k%29*sin%28k%2B1%29%29 something like 1.355867228946
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
Great!!!!!! Thanks @Recursing . But I want to know the procedure.
 2 years ago

RecursingBest ResponseYou've already chosen the best response.0
wolframalpha can't find a way to simplify it, if wolframalpha can't I'm sure that it's waaay beyond my level of math knowledge, and I think it's probably impossible to reduce it.
 2 years ago

RecursingBest ResponseYou've already chosen the best response.0
Oh, wait, i used radians.
 2 years ago

RecursingBest ResponseYou've already chosen the best response.0
Well, it doesn't get much better http://www.wolframalpha.com/input/?i=sum_%28k%3D45%29%5E133+1%2F%28sin%28k*pi%2F180%29*sin%28%28k%2B1%29*pi%2F180%29%29 The partial sums graph looks close to a line, maybe? http://www.wolframalpha.com/input/?i=sum_%28k%3D45%29%5E133+1%2F%28sin%28k%C2%B0%29*sin%28%28k%2B1%29%C2%B0%29%29
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
@Mani_Jha , @Taufique , @AravindG , @gurvinder bhai, please try once more.
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
@salini , @shruti , @rebeccaskell94 , @KatrinaKaif please try.
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
Actually, its a 3 mark question. I just guessed and wrote answer as "1". I don't know how much marks I may have got. But just waiting for over 6 months to get the rite answer. Hope u all help.
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
@wasiqss , @lgbasallote , @sheena101 , @Akshay_Budhkar , @Ishaan94 please try
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
@Sarkar , @payalvsangle , @heena , @apoorvk please try.
 2 years ago

Mani_JhaBest ResponseYou've already chosen the best response.0
I've tried again like this: \[1/\sin133\sin134=1/\sin46\sin47\] \[1/\sin132\sin131=1/\sin48\sin49\] Similarly, for every term from the right. Finally, \[1/\sin91\sin92=1/\sin89\sin88\] Now we'll add these fractions. \[(\sin47\sin48..\sin89)+(\sin45\sin46\sin49..\sin50).......(\sin45\sin46\sin47\sin50..\sin89)\] +\[(\sin45\sin48..\sin89)(\in numerator)\] Denominator= \[(\sin45\sin46.........\sin89)\] Now we'll add the first and last, then second and second last and so on in the numerator. \[((\sin48.\sin89)(\sin45+\sin47)+\sin45\sin46..\sin89(\sin47+49)......)/(\sin45..\sin89)\] Now use sinA+sinB=2sin(A+B)/2cos(AB)/2 \[(\sin48..\sin ^{2}88\sin89+\sin45..\sin ^{2}84\sin89...)/(\sin45\sin46...)\] sin88 gets cancelled from the denominator. \[(\sin48..\sin89(\sin88+\sin84.....\sin48))/\sin45..\sin89\]
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
So, final answer = ? I could n't understand clearly.
 2 years ago

Ishaan94Best ResponseYou've already chosen the best response.1
Aadarsh? Is it [1/(sin 45 sin 46)] + [1/(sin 47 sin 48)] + .... + [1(sin 133 sin 134)], or [1/(sin 45 sin 46)] +[1/(sin46 sin47)]+ [1/(sin 47 sin 48)] +...+ [1(sin 133 sin 134)]
 2 years ago

Ishaan94Best ResponseYou've already chosen the best response.1
\[\large \sum_{k=0}^{44} \frac1{\sin(45+2k)\cdot\sin(45+2k+1)}\]
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
How tro solve it? What is the final answer?
 2 years ago

Ishaan94Best ResponseYou've already chosen the best response.1
\[\large \sum_{k=0}^{44} \frac{2}{(\sin2k + \cos 2k)(\sin(2k+1) + \cos(2k+1))}\] No idea lol I will have to think about it.
 2 years ago

Ishaan94Best ResponseYou've already chosen the best response.1
\[\large \sum_{k=0}^{44} \frac{2}{\sin(4k+1) + \cos 1}\]
 2 years ago

Ishaan94Best ResponseYou've already chosen the best response.1
This must be a Multiple Choice Question, what are the options?
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
Subjective Question, 3 marks
 2 years ago

Ishaan94Best ResponseYou've already chosen the best response.1
I have a feeling something is missing :/ http://www.wolframalpha.com/input/?i=\sum_{k%3D0}^{44}+\frac{2}{\sin%284k%2B1%29+%2B+\cos+1}
 2 years ago

TaufiqueBest ResponseYou've already chosen the best response.4
@Aadarsh read the attach file
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
Greta answer @Taufique bhai. Thanks a lot.
 2 years ago

TaufiqueBest ResponseYou've already chosen the best response.4
@Aadarsh Welcome Aadarsh ji...
 2 years ago

AadarshBest ResponseYou've already chosen the best response.2
Welcome bhaijan............
 2 years ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.