Differentiation

y2+x2=R2 and k=1/R,then k is equal to

a)IyI/√1+(y')2

b)Iy''I/√[1+(y')2]3

c)2Iy"I/√1+(y')2

d)Iy"I/2√(1+(y')2)3
also tell hw to solve

27 Answers

11
Anirudh Narayanan ·

But still representing a constant in terms of variables is against logic, isn't it?

1
greatvishal swami ·

R iss constantt & thnx 4 dat corrction

1
Honey Arora ·

u hv given the sol...........bt hw to solve it?........r we going to consider R constant here?
nd srry i hd put wrong 2nd option bt nw i hv corrected it

1
greatvishal swami ·

sry ani i m too lazy to get that maths book whose location i dont know i will giv post it 2morow on ur scrap bt its frm the topic higher order differentiation u can easily find it

1357
Manish Shankar ·

For any curve y=f(x)

k(curvature)=y''/(1+y'2)3/2

Radius of curvature R=1/k

for circle k=constant

11
Anirudh Narayanan ·

NCERT[11]? Pls give pg number and q number.

1
greatvishal swami ·

yup wat bhaiya is saying is correct & Q is from NCERT & now i dont thnk whole indian mathematicians r moorkh :D

11
Anirudh Narayanan ·

Bhaiyyah, didn't get ur solution.[2]

1357
Manish Shankar ·

given K is a general term for the curvature of a curve which is the inverse of radius of curvature.

Radius of curvature R=(1+y'2)3/2/y''

K(curvature)=1/R

Here in case of circle it is constant

11
Anirudh Narayanan ·

ratio can be a constant but who said it is. Abt the question setter i think u better ask honey.

1
greatvishal swami ·

yup mr variable bt isnt it is the ratio & ratio can be constant & Q setter is not a moorkh i suppose :P

11
Anirudh Narayanan ·

A value which u can represent by variables is no longer a constant as it varies with variation in the variable :p

1
greatvishal swami ·

see the options K is given in ratio ho sakta hai ki ratio const. rahe hamesha

also agar y chane karega to y' aur y'' bhi change karega

so i think in ratio they will like neutralize each others effect(kind of)

1
skygirl ·

i fully agree with aragorn..

wats the point of finding out a constant in terms of variables...

11
Anirudh Narayanan ·

k is a constant. But y' and y" are variables. So how can k be in terms of y' and y"?[7]

1
greatvishal swami ·

u can clearly se that we dont want x, y in the result so diff it two times name them 1 , 2 now put value of y from 2 in 1 also put x from initial eqn in 1 u will get smethin in R,y',y''
so u can easily find K

11
Anirudh Narayanan ·

Honey said she got it from a book. She actually saw 2 questions. One is the question which posted as a test and the other one is this question.

1
Akshay Pamnani ·

Where did u get this question??

11
Anirudh Narayanan ·

You can form a de but can you bring k into it?

1
greatvishal swami ·

i can show it :D

i actually proved it bt i m really sure that something is seriously wrong with the options given
i m not actually getin opt b

11
Anirudh Narayanan ·

k is a constant. But y' and y" are variables. So how can k be in terms of y' and y"? [7]

1
greatvishal swami ·

ans is b

1
Honey Arora ·

cn anyone plz ans this?

11
Anirudh Narayanan ·

There is no ans to it; so don't worry.

1
Honey Arora ·

i don't know this ws the ques nd these options......i don't know hw to solve it

11
Anirudh Narayanan ·

R is a constant. It's the eqn of a circle with center at O and radius R

1
Honey Arora ·

if i knew i wldn't hv posted it here..........i m also confused bout the same thing:whether to tk R as cnstnt or nt coz if we tk thn it wld bcm 0 after differentiation
who hs said 'k' is constant

Your Answer

Close [X]