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Find the no. of distinct elements in

{(1+ω+ω2+ω3+....+ωn)m :m,n=1,2,3,...}

14 Answers

1
ANKIT MAHATO ·

5 .. elements

1
ANKIT MAHATO ·

1 , ω2 , ω , -ω2 , 0

13
Двҥїяuρ now in medical c ·

nope...

1
ANKIT MAHATO ·

yup i missed -1 n -ω .. total 7

13
Двҥїяuρ now in medical c ·

yup...but watz the method??....only trial??

at first try i missed -ω,-ω2...:(

1
ANKIT MAHATO ·

simplifying the bracket u will get 3 options
....(1)m
....(1 + ω)m
... (0)m

so u get 2 ans 0 n 1

now (1 + ω)m = (-ω2)m = -ω2 , ω2 , -ω , ω , -1 , 1 for diff. values of m

13
Двҥїяuρ now in medical c ·

easy one....

\lim_{x\rightarrow \frac{\pi }{2}}sinx^{tanx}

1
ANKIT MAHATO ·

tan x ln sinx ... write it as ln sinx / cot x ... L hospital ... cot x / - cosec2 x .. .this quantity is 0 as sin x cos x = 0 ....... so limit = ε0 = 1

1
ANKIT MAHATO ·

oye kuch bata toh ?????

13
Двҥїяuρ now in medical c ·

thanks!

this one....

a,b,c real and distinct

no. of real soln of

(x-a)3+(x-b)3+(x-c)3=0

1
gordo ·

let F(x)=(x-a)3+(x-b)3+(x-c)3
lim x->+∞ F(x)-> +∞
lim x->-∞ F(x)-> -∞

F'(x)=3(x-a)2+3(x-b)2+3(x-c)2
we see that F'(x)>0 for all real x in the domain which means that
F(x) is increasing in the domain (-∞,+∞)
and F(x) is differentiable and continuous in its domain
=> F(x) has one and only one real root in the domain..
cheers!!!

1
ANKIT MAHATO ·

:) ... yup u r correct gordo

13
Двҥїяuρ now in medical c ·

a,b,c real and positive

prove that

\[ \frac{1}{b(a+b)}+\frac{1}{c(b+c)}+\frac{1}{a(c+a)}\geq\frac{27}{2(a+b+c)^{2}}. \]

13
Двҥїяuρ now in medical c ·

plz help!

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