作业帮为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/03 20:56:29
![为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]](/uploads/image/z/5248412-44-2.jpg?t=%E4%B8%BA%E4%BB%80%E4%B9%88%E6%98%AF%E2%88%B5x%E2%88%88%E3%80%900%2C%CF%80%2F2%E3%80%91%E2%88%B42x-%CF%80%2F4%E2%88%88%5B-%CF%80%2F4%2C3%CF%80%2F4%5D%E4%B8%BA%E4%BB%80%E4%B9%88%E6%98%AF%E2%88%B5x%E2%88%88%E3%80%900%2C%CF%80%2F2%E3%80%91%E2%88%B42x-%CF%80%2F4%E2%88%88%5B-%CF%80%2F4%2C3%CF%80%2F4%5D)
为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]
为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]
为什么是∵x∈【0,π/2】
∴2x-π/4∈[-π/4,3π/4]
为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]为什么是∵x∈【0,π/2】∴2x-π/4∈[-π/4,3π/4]
∵x∈[0,π/2] 两边同乘以2
∴2x∈[0,π] 两边同减去π/4
∴2x-π/4∈[0-π/4,π-π/4]=[-π/4,3π/4]