Question:medium
If $f(x) = \sec x - \cot x$, then $f'\!\left(\dfrac{\pi}{6}\right)$ equals
If $f(x) = \sec x - \cot x$, then $f'\!\left(\dfrac{\pi}{6}\right)$ equals
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$\dfrac{d}{dx}(\sec x) = \sec x\tan x$; $\dfrac{d}{dx}(\cot x) = -\csc^2 x$. Note the sign: $f = \sec x - \cot x$, so $f' = \sec x\tan x + \csc^2 x$.
Updated On: Apr 8, 2026
- $-3$
- $\dfrac{14}{3}$
- $\dfrac{11}{3}$
- 5
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The Correct Option is B
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