Question

化简(sin(α-2π)cos(α+π)tan(α-99π))/(cos(π-α)sin(3π-α)sin(-α-π))

Answer 1

(sin(α-2π)cos(α+π)tan(α-99π))/(cos(π-α)sin(3π-α)sin(-α-π))
=(sin(-(2π-α))cos(α+π)tan(-(100π-(α+π)))/(cos(π-α)sin(2π-(α+π))sin(-(α+π))
=(sinαcosαtan(100π-(α+π))/(cosα sin(α+π) sinα)
=(sinα cosα tan(α+π)/(cosα sinα sinα)
=(sinα cosα tanα)/(cosα sinα sinα)
=tanα/ sinα
=sinα/ (sinα cosα)
=1/ cosα