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Question:

limx→0sin(πcos2x)x² is equal to

1

−π

π

π²

Solution:

Let L=limx→0sin(πcos2x)x²
=limx→0sin(π(1−sin²x))x²
=limx→0sin(π−πsin²x)x²
=limx→0sin(πsin²x)x² (sin(π−θ)=sinθ)
Multiplying and dividing by πsin²x. We get,
=limx→0sin(πsin²x)πsin²x × πsin²xx²
We know that, limx→0sinxx=1
∴L=π