Class 11MathematicsTrigonometrical Ratios, Functions and IdentitiesTrigonometrical ratios of sum and difference of two and three angles
EasyIf $\cos (A + B) = \alpha \cos A \cos B + \beta \sin A \sin B,$ then $(\alpha, \beta) =$
- A$(-1, -1)$
- B$(-1, 1)$
- C$(1, -1)$
- D$(1, 1)$
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Similar Questions
If $\cos \theta = \frac{8}{17}$ and $\theta$ lies in the $1^{st}$ quadrant,then the value of $\cos (30^\circ + \theta) + \cos (45^\circ - \theta) + \cos (120^\circ - \theta)$ is
Medium
View SolutionIf $x + y = \frac{\pi}{4}$, then $(1 + \tan x)(1 + \tan y) =$
DifficultMHT CET 2026
View SolutionIf $\cos (\alpha + \beta ) = \frac{4}{5}$,$\sin (\alpha - \beta ) = \frac{5}{13}$ and $\alpha, \beta$ lie between $0$ and $\frac{\pi}{4}$,then $\tan 2\alpha = $
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View SolutionIf $\frac{x}{\cos \theta} = \frac{y}{\cos \left( \theta - \frac{2\pi}{3} \right)} = \frac{z}{\cos \left( \theta + \frac{2\pi}{3} \right)},$ then $x + y + z = $
Medium
View Solution$\tan 15^\circ = $
Easy
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