Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
sritama
Group Title
prove, f(x)=xcos1/x (when x not = 2)
=0 (when x=0)
f(x) is continuous at the point x=0
 2 years ago
 2 years ago
sritama Group Title
prove, f(x)=xcos1/x (when x not = 2) =0 (when x=0) f(x) is continuous at the point x=0
 2 years ago
 2 years ago

This Question is Closed

saubhik Group TitleBest ResponseYou've already chosen the best response.2
is your function f(x)=xcos(1/x) (when x not 0) =0 when x=0 ?
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
yes yes. i am wrong xnot 0
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
\[\lim_{x \rightarrow 0+}xcos(1/x)=\lim_{x \rightarrow 0}xcos(1/x)=f(0)=0\] hence continuous at x=0.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
if you are wondering why \[\lim_{x \rightarrow 0+}xcos(1/x)=0\] then note that \[1\leq \cos(1/x)\leq 1\ for\ all\ x.\] So \[\lim_{x \rightarrow 0}xcos(1/x)=\lim_{x \rightarrow 0}x\cdot a=a \lim_{x \rightarrow 0}x=0\] here a is any real value between 1 and 1.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
in which class u are?
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
class 11.u?
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
me in college 1st year:) which city u?
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
whic school..i am in kolkata
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
khidirpur st.thomas
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
cbse? if u need help regarding math problems u can ask me! i can suggest a great math book for classes 11 and 12!
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
oh , say the name.can u suggest some books for mathematical olympiad?
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
your college?
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
yeah! I am in Jadavpur University (Mech Engg) for school to IIT level problems: Problems Plus In IIT Mathematics by Asit Dasgupta
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
the book by asit dasgupta is great for the basics but for RMO,INMO u need to try some other books...
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
did u appear for RMO/INMO any time.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
yes one time in class 11:was not well prepared:( didnt get through...u need tough preparations for RMO...however if u r a genius u dont need much preparataions!
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
are u good in probability?it is tough to me.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
u can try me. :)
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
i have no hard problem at present.when i found a very hard problem,i would ask u .
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
u can call me (if u want my cell no. u can ask me now) or u can mail me to saubhik.mukherjee@gmail.com...i dont come to openstudy often..so u can take my phone no. or gmail
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
ok.i will mail u.however do u have interest in astrophysics.it is my most fav.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
about me: i got 100 in maths in class 12 and 100 in class 10 CBSE. I love olympiad mathematics and want to help anyone interested in olympiad maths. about astrophysics:there is an olympiad for that and I dont know anything about it :)
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
wow.u r so brilliant!
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
thanks.hope to help u soon :)
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
in triangle ABC,AB=AC,A is right angle.M & N are 2points on BC satisfying BM^2+CN^2=MN^2. prove that angle MAN=45.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
I proved it using coordinate geometry. Did not get a good pure geometry solution though. I can show you the proof. You can post this as a separate question.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
wait...i will attach a picture wait 2 min.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
did u see the picture? The side AB is on yaxis and AC is on xaxis...
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
yes i did and understand.thanks a lot !!!but whenever u get pure geometry solution please post,30 MEDALS for u.
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
i did not explain anything..u got it? u have to use the distance formula to obtain a relation and then use this relation in another equation which u will get by considering the angle between the two lines AM and AN, which u can get by considering the slopes of the two lines AM and AN. did u get this angle as 45 degrees?
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
what's your email id?
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
yes my elder sister helped me
 2 years ago

sritama Group TitleBest ResponseYou've already chosen the best response.0
it is chowdhurysaugata6@gmail.com ok
 2 years ago

saubhik Group TitleBest ResponseYou've already chosen the best response.2
ok...any more problems u can always ask me:)
 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.