Math, asked by manu1121, 1 year ago

plz answer ques 10 .... plzzz i will be grateful

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Aaryadeep: just wait bro for a picture... well are you in class 9 ?
manu1121: yss
Aaryadeep: i m also in class 9 :-)
manu1121: gudd
manu1121: can u answer me one more question
Aaryadeep: yes sure is it this one or any other

Answers

Answered by tanu66
2
I just tried.... hope this helps..
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manu1121: thankss
tanu66: welcome
Answered by Aaryadeep
2
hi see this pic for your answer
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afsharshaikh67: wait a minute I have some work.....
Aaryadeep: hey bro if you put x=√-2 then there will be two zero and the question say that it has one zero
afsharshaikh67: yes...but we cannot write -√2.... so in complex no. i²= -1 therefore = (√2i)^3 - 3(√2i)^2 + 2√2i - 6= 2√2i^3 - 3×2×i^2 + 2√2i - 6 = -2√2i + 6 + 2√2i - 6 = 6-6 = 0 hence proved...
afsharshaikh67: no bro...it has one zero only..you can try this steps...
afsharshaikh67: Supposing you mean: 
p(x) = x^3 - 3x^2 + 2x - 6 
This is a cubic equation, so it has three zeros by its nature. 
use the rational roots theorem to find the root at x = 3. 
Use the factor theorem to convert this root into a factor: 
(x - 3) 
Divide by the known factor: 
(x^3 - 3x^2 + 2x - 6) / (x - 3) = x^2 + 2 
Use the zero product principle: 
x^2 + 2 = 0 
Subtract 2: 
x^2 = -2 
Take the square root: 
x = ± i √2 where i^2 = -1 
So what's been shown is that p(x) has only one REAL zero.
afsharshaikh67: & another is complex root
afsharshaikh67: & for your kind information manu1121 we cannot write -√2 in this ex.
manu1121: thanks for ur help afshar ... thnku
afsharshaikh67: it's ok bro
Aaryadeep: hmm i got it
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