Math, asked by Anonymous, 11 months ago

solve it very hard Question
If a,b,c are G.P then a+b+c=xb. Then x≠.​

Answers

Answered by khushi02022010
4

Step-by-step explanation:

General team of a GP -

tn =  {af}^{n}  - 1

_ When ein

a => First team

r => Common ratio

From the concept have teams be

Let the three teams be

b/r, b, be => in GP

Given: a + br = x b

 =  \frac{b}{r}  + b \:  + br = xb

 =  \frac{1}{r}  + 1 + r = x

 = x - 1 = r +  \frac{1}{r}

Hope it's help you....

Answered by Anonymous
48

 \fcolorbox{pink}{white} {\tt{answer}}

a,b,c are \:  in \:  GP

Let \:  'r'  \: be  \: the  \: common  \: ratio \:  then,

 \frac{b}{a}  = r \:  \:  =  > a =  \frac{b}{r}

also,

 \frac{c}{b}  = r \:  \:  \:  =  >c = br

 \therefore \: a + b + c =  \frac{b}{r}  + r + br = b( \frac{1 + r +  {r}^{2} }{r} )

if \: a + b + c = xb

then \: ( \frac{1 + r +  {r}^{2} }{r} ) = x

 \boxed{if \: r < 0 \: and \: r ≠ - 1}

( \therefore \: a,b,c  \: are \:  3 \: distinct \: no.)

Then,

 \frac{1 + r +  {r}^{2} }{r}  = x

 =  >  \frac{1 + r +  {r}^{2} }{r}  + 1 = x + 1

 =  >  \frac{(1 + r {)}^{2} }{r}  = x

 \therefore \: r < 0

There \:  by, \:  \frac{(1 + r {)}^{2} }{r}  < 0( \therefore \: (1 + r {)}^{2}  > 0)

 =  > x + 1 < 0

 =  > x <  - 1

\boxed{if\:r>0\:and\:r≠1}

then, \:\frac{1 + r +  {r}^{2} }{r}=x \: \: =>\frac{1 + r +  {r}^{2} }{r} - 3=x-3

 =  >  \frac{(r-1{)}^{2} }{r}=x-3

Again\:\frac{(r-1{)}^{2} }{r}>0(\therefore \:r>0\: and\:(1+r)^{2}<0)

=>r-3>0

=>r>3

∴    x∈(−∞,−1)∪(3,∞)

\small{\boxed{\pink{Hence,\:x\:can\: not\:be\:2}}}

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