“第二个答案由[0,π)内,π/3=π/3=1/,结合余弦线就能得出α≤1/的解集,最难的部分其实是第三个,已知[0,π)内,|π/4|=|π/4|=|3π/4|=|3π/4|=|π/4|=|π/4|=|7π/4|=|7π/4|=√ ̄/,结合余弦线和正弦线,所以|α|>|α|的解集为{α|kπ-π/4<α<kπ+π/4,k∈z},你看,是不是很简单?” 整段话说完,余华微微喘气,