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Question: Answered & Verified by Expert
The sum of the roots of the equation e4t-10e3t+29e2t-22et+4=0 is
MathematicsQuadratic EquationAP EAMCETAP EAMCET 2021 (19 Aug Shift 1)
Options:
  • A loge10
  • B 2loge2
  • C log229
  • D 2log102
Solution:
2391 Upvotes Verified Answer
The correct answer is: 2loge2

Let x=ett=logex

Then, the given equation reduces to x4-10x3+29x2-22x+4=0

Now, product of roots taken all at a time of a biquadratic equation is constant termcoefficient of x2.

Let x1, x2, x3 and x4 are the four roots of x4-10x3+29x2-22x+4=0, then x1x2x3x4=41=4.

Taking log both sides, we get logex1x2x3x4=loge4

logex1+logex2+logex3+logex4=2loge2

t1+t2+t3+t4=2loge2

Where t1, t2, t3 and t4 are the roots of the equation e4t-10e3t+29e2t-22et+4=0.

Hence, sum of roots is 2loge2.

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