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高一数学2cosx乘√2sin(x+π/4)化简

题目详情
高一数学2cosx乘√2sin(x+π/4)化简
▼优质解答
答案和解析
2cosx乘√2sin(x+π/4)
= 2cosx ×√2sin(x+π/4)
= 2cosx ×√2 ×{sinx sin(π/4) + cosx cos(π/4)}
= 2cosx ×√2 ×{√2/2×sinx + √2/2×cosx }
= 2cosx ×√2 ×√2/2×(sinx + cosx )
= 2cosx ×(sinx + cosx )
= 2 sinx cosx + 2 cos²x
= sin(2x) + cos(2x) + 1