The expression 3 + 3 + is to be simplified.

MATHEMATICS · Multi-part · CBSE · Mathematics · Trigonometric Functions · Trigonometric Functions

Problem

The expression sin⁡3θ+sin⁡θcos⁡3θ+cos⁡θ\dfrac{\sin 3\theta+\sin\theta}{\cos 3\theta+\cos\theta} is to be simplified. (i) Show that the expression simplifies to tan⁡2θ\tan 2\theta for all values of θ\theta for which it is defined. (ii) Using the result of part (i), calculate the numerical value of sin⁡75∘+sin⁡25∘cos⁡75∘+cos⁡25∘.\dfrac{\sin75^{\circ}+\sin25^{\circ}}{\cos75^{\circ}+\cos25^{\circ}}.

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