MCQ
$\cos ^4 \theta-\sin ^4 \theta=\ldots \ldots \ldots .$.
- A$2 \cos ^2 \theta+1$
- B$2 \sin ^2 \theta+1$
- ✓$2 \cos ^2 \theta-1$
- D$2 \sin ^2 \theta-1$
✓
Answer
Correct option: C.
$2 \cos ^2 \theta-1$
$2 \cos ^2 \theta-1$
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