JEE MainMathematicsQuadratic Equation and InequalitiesMCQ+4 / −1
The sum of the roots of the equation , is :
- Alog2 14
- Blog2 11
- Clog2 12
- Dlog2 13
View written solutionFree
Correct answer: B
- Given equation
We need the sum of all roots.
- Convert everything to base 2
Recall:
So,
Hence the equation becomes
Also,
Thus
Therefore,
Using log laws,
So,
That is,
- Substitute
Since , let
Then the equation becomes
Simplify:
- Solve the quadratic
Using the quadratic formula,
So the two possible values are
Both are positive, so both are valid since .
Thus roots are
- Find the sum of roots
- Match with options
So the correct option is B.
- Comparison with stored answer
Stored correct answer: B
Our derived answer: B
They agree.
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