If sinA + sin2A = 1, then the value of the expression (cos2A + cos4A) is ______.

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If sinA + sin2A = 1, then the value of the expression (cos2A + cos4A) is 1. Explanation: Given, sinA + sin2A = 1 ⇒ sinA = 1 – sin2A = cos2A ...[∵ sin2θ + cos2θ = 1] On squaring both sides, we get sin2A = cos4A ⇒ 1 – cos2A = cos4A ⇒ cos2A + cos4A = 1

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