WBJEE · Maths · Trigonometric Ratios & Identities
The value of \(\cos 15^{\circ} \cos 7 \frac{1^0}{2} \sin 7 \frac{1^0}{2}\) is
- A \(\frac{1}{2}\)
- B \(\frac{1}{8}\)
- C \(\frac{1}{4}\)
- D \(\frac{1}{16}\)
Answer & Solution
Correct Answer
(B) \(\frac{1}{8}\)
Step-by-step Solution
Detailed explanation
\begin{aligned} & \text { Hints : } \cos 15^{\circ} \cos 7 \frac{1}{2}^0 \sin 7 \frac{1}{2}^0=\frac{1}{2}\left(2 \sin 7 \frac{1}{2}^0 \cos 7 \frac{1}{2}^0\right) \cdot\left(\cos 15^{\circ}\right) \\ & \frac{1}{2}\left(\sin 15^{\circ}\right)\left(\cos…
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