Math, asked by yashdeep8, 1 year ago

ffffffffiiiinnnnnnndddddd​

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Anonymous: Mate mark my Ans as brainlist if it helps you!!:-)

Answers

Answered by Abhinavsingh34133
0

Answer:

6,18

Step-by-step explanation:

plz mark me brainlist

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yashdeep8: x4+1/x4?
Abhinavsingh34133: just square x2+1/x2
yashdeep8: explain
Answered by Anonymous
6

Given \:  \: Question \:  \: Is \:  \:  \:  \\  \\ x +  \frac{1}{x}  = 3 \\  \\ 01 \\ \\  find \:  \: x {}^{2}  +  \frac{1}{x {}^{2} }  \\  \\ Answers \:  \:  \:  \\  \\ x +  \frac{1}{x}  = 3 \\  \\ squaring \:  \: on \:  \: both \:  \: sides \:  \: we \:  \: have \\  \\ (x +  \frac{1}{x} ) {}^{2}  = (3) {}^{2}  \\  \\ x {}^{2}  +  \frac{1}{x {}^{2} }  + 2x \frac{1}{x}  = 9 \\  \\ x {}^{2}  +  \frac{1}{x {}^{2} }  + 2 = 9 \\  \\ x {}^{2}  +  \frac{1}{x {}^{2} }  = 9 - 2 \\  \\ x { }^{2}  +  \frac{1}{x {}^{2} }  = 7 \\  \\ Therefore \:  \:  \:  \:  \:  \:  \: x {}^{2}  +  \frac{1}{x {}^{2} }  = 7 \\  \\  \\ 02 \\  \\ find \:  \:  \:  \:  \:  \:  \:  \:  \: x {}^{3}  +  \frac{1}{x {}^{3} }  \\  \\ Answer \:  \\  \\ x +  \frac{1}{x}  = 3 \\  \\ cubing \:  \:  \: on \:  \: both \:  \: sides \:  \: we \:  \: have \\  \\ (x +  \frac{1}{x} ) {}^{3}  = (3) {}^{3}  \\  \\  \\ x {}^{3}  +  \frac{1}{x {}^{3} }  + 3(x +  \frac{1}{x} ) = 27 \\  becoz \:  \:  \: (a + b) {}^{3}  = a {}^{3}  + b {}^{3}  + 3ab(a + b) \\  \\  \\ x {}^{3}  +  \frac{1}{x {}^{3} }  + 3(3) = 27 \\  \\  \\ x {}^{3}  +  \frac{1}{x {}^{3} }  + 9 = 27 \\  \\ \\  x {}^{3}  +  \frac{1}{x {}^{3} }  = 27 - 9 \\  \\  \\ x {}^{3}  +  \frac{1}{x {}^{3} }  = 18 \\  \\  \\ Therefore \:  \:  \:  \:  \:  \:  \:  \:  \: x {}^{3}  +  \frac{1}{x {}^{3} }  = 18 \\  \\  \\ 03 \\  \\ find \:  \:  \:  \:  \:  \: x {}^{4}  +  \frac{1}{x {}^{4} }  \\  \\ Answer \:  \\  \\ x {}^{2}  +  \frac{1}{x {}^{2} }  = 7 \\  \\ squaring \:  \: on \: \:  both \:  \: sides \:  \: we \:  \: have \\  \\ (x {}^{2}  +  \frac{1}{x {}^{2} } ) = (7) {}^{2}  \\  \\  \\ x {}^{4}  +  \frac{1}{x {}^{4} }  + 2x {}^{2}  \frac{1}{x {}^{2} }  = 49 \\  \\  \\ x {}^{4}  +  \frac{1}{x {}^{4} }  + 2 = 49 \\  \\  \\ x {}^{4}  +   \frac{1}{x {}^{4} }  = 49 - 2 \\  \\  \\ x {}^{4}  +  \frac{1}{x {}^{4} }  = 47 \\  \\  \\ Therefore \:  \:  \:  \:  \:  \: x {}^{4}  +  \frac{1}{x {}^{4} }  = 47

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