化简[sin(π-α)cos(3π-α)tan(-α-π)]/[tan(4π-α)sin(5π+α)]
问题描述:
化简[sin(π-α)cos(3π-α)tan(-α-π)]/[tan(4π-α)sin(5π+α)]
答
sin(π-a)cos(3π-a)tan(-π-a)tan(a-2π)/tan(4π-a)sin(5π+a)
=sinacosatana/tanasina
=cosa