∴當(dāng)k為偶數(shù)時(shí),原式=
?sinα?(?cosα) |
?sinα?cosα |
當(dāng)k為奇數(shù)時(shí),原式=
sinα?cosα |
sinα?(?cosα) |
綜上所述,k∈Z,
sin(kπ?α)cos[(k?1)π?α] |
sin[(k+1)π+α]cos(kπ+α) |
故選A.
sin(kπ?α)cos[(k?1)π?α] |
sin[(k+1)π+α]cos(kπ+α) |
?sinα?(?cosα) |
?sinα?cosα |
sinα?cosα |
sinα?(?cosα) |
sin(kπ?α)cos[(k?1)π?α] |
sin[(k+1)π+α]cos(kπ+α) |