化简（-11/6 π)+cos(12/5 π)tan（4π）-1/(cos(13π/3))
问题描述：
化简（-11/6 π)+cos(12/5 π)tan（4π）-1/(cos(13π/3))
答
(-11/6 π)+cos(12/5 π)tan(4π) - 1/(cos(13π/3))
=-11π/6 - 1/cos(π/3)
=-11π/6 - 2