Question

化简：

sin2(α+π)•cos(π+α)

tan(π+α)•cos3(-α-π)•tan(-α-2π)

．

Answer 1

原式=

(-sinα)2•(-cosα)

tanα•cos3(π+α)•[-tan(2π+α)]

=

sin2α•(-cosα)

tanα•(-cosα)3•(-tanα)

=-

sin2α•cosα•cotα

tanα•cos3α

=-1