JEE MainMathematicsQuadratic Equation and InequalitiesMCQ+4 / −1
If an angle A of a ABC satiesfies 5 cosA + 3 = 0, then the roots of the quadratic equation, 9x2 + 27x + 20 = 0 are :
- AsecA, cotA
- BsinA, secA
- CsecA, tanA
- DtanA, cosA
View written solutionFree
Correct answer: C
- Given condition on the angle
We have So,
Since is an angle of a triangle, . Also , so is obtuse and hence .
Therefore,
Now compute the required trigonometric values:
- Solve the quadratic equation
Given:
Factorize:
So the roots are
- Match with trigonometric values
We found:
These are exactly the roots of the quadratic equation.
So the roots are:
- Check options
- A: ❌
- B: ❌
- C: ✅
- D: ❌
Hence, the correct option is C.
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