解
sin⁴α+sin²αcos²α+cos²α
=sin²a(sin²a+cos²a)+cos²a
=sin²a×1+cos²a=sin²a+cos²a
=1sin⁴α+sin²αcos²α=sin²a(sin²a+cos²a)解析下有点不懂因为sin⁴α=sin²a×sin²a∴sin⁴α+sin²αcos²α提取sin²a=sin²a(sin²a+cos²a)