if x= c√b + 4, Find x + 1/ x.
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x = c√b + 4
1/x = 1/(c√b + 4)
= x + (1/x)
by putting the value of both,we get
(c√b + 4) + [1/(c√b + 4)]
= [(c√b + 4)² + 1]/(c√b + 4)
= [bc² + 8c√b + 16 + 1]/(c√b + 4)
= [bc² + 8c√b + 17]/(c√b + 4) →after rationalising we get
= [(bc² + 8c√b + 17).(c√b - 4)] / [(c√b + 4).(c√b - 4)]
= [bc³√b - 4bc² + 8bc² - 32c√b + 17c√b - 68] / (bc² - 16)
= [bc³√b + 4bc² - 15c√b - 68] / (bc² - 16).
1/x = 1/(c√b + 4)
= x + (1/x)
by putting the value of both,we get
(c√b + 4) + [1/(c√b + 4)]
= [(c√b + 4)² + 1]/(c√b + 4)
= [bc² + 8c√b + 16 + 1]/(c√b + 4)
= [bc² + 8c√b + 17]/(c√b + 4) →after rationalising we get
= [(bc² + 8c√b + 17).(c√b - 4)] / [(c√b + 4).(c√b - 4)]
= [bc³√b - 4bc² + 8bc² - 32c√b + 17c√b - 68] / (bc² - 16)
= [bc³√b + 4bc² - 15c√b - 68] / (bc² - 16).
Himanshusekhar:
I've got this answer But the problem is in Pearson book this is not the answer
sorry bro.
I think the book answer is worng
If I'm not wrong
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