NTA Abhyas 2020
- Exam
- NTA Abhyas
- Year
- 2020
- Subject
- Mathematics
- Chapter
- Differentiation
NTA Abhyas 2020 · Mathematics · Differentiation
If f(x) = ||2sin x - 1| - 2cot x| , then the value of f ^ '...
If , then the value of is equal to
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
In the neighbourhood of , we know,
\left(2sin x - 1\right) > 0⇒ f\left(x\right) = \left|\left(2sin x - 1\right) - 2cot x\right|x = \dfrac{\pi}{3}2sin x - 1 - 2cot x = 2\left(\dfrac{\sqrt{3}}{2}\right) - 1 - \dfrac{2}{\left(\sqrt{3}\right)} = \dfrac{3 - 2}{\sqrt{3}} - 1= \dfrac{1}{\sqrt{3}} - 1 < 0∴ f\left(x\right) = \left(2cot x\right) - \left(2sin x - 1\right){f}^{'}\left(x\right) = 2\left(- cose{c}^{2}x\right) - 2cos x{f}^{'}\left(\dfrac{\pi}{3}\right) = 2{\left(- \dfrac{2}{\sqrt{3}}\right)}^{2} - 2\left(\dfrac{1}{2}\right)= 2\dfrac{4}{3} - 1 = \dfrac{5}{3}$