cos(α-3π)×tan(α-4π)/sin(3π-α)×cot(α+5π)
=(4/5-3/4)/(3/5-4/3)
=-3/44兄弟你做错了是吗，我在算算。cos(α-3π)=-cosα=4/5tan(α-4π)=tanα=-3/4sin(3π-α)=3/5cot(α+5π)=cotα=-4/3cos(α-3π)×tan(α-4π)/sin(3π-α)×cot(α+5π)=[4/5*(-3/4)]/[3/5*(-4/3)]=3/4不好意思，我按和计算了，抱歉。