COMEDK · Maths · 8. Trigonometric Ratios & Identities
If \(\sin x+\sin ^2 x=1\) then \(\cos ^8 x+2 \cos ^6 x+\cos ^4 x\) is equal to
- A \(0\)
- B \(1\)
- C \(-1\)
- D \(2\)
Answer & Solution
Correct Answer
(B) \(1\)
Step-by-step Solution
Detailed explanation
Given \(\sin x + \sin^{2} x = 1\). This implies \(\sin x = 1 - \sin^{2} x = \cos^{2} x\). We need to evaluate \(\cos^{8} x + 2 \cos^{6} x + \cos^{4} x\). Substituting \(\cos^{2} x = \sin x\), we get:…
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