Question

求方波与正弦波的傅里叶级数要求写出方波和正弦波的傅里叶级数（三角函数展开）的前五项.要求频率为200赫兹,振幅任意.请赐

Answer 1

振幅为1的方波展开前10项:

(4Sin[tω])/π,

(4Sin[3tω])/(3π),

(4Sin[5tω])/(5π),

(4Sin[7tω])/(7π),

(4Sin[9tω])/(9π),

(4Sin[11tω])/(11π),

(4Sin[13tω])/(13π),

(4Sin[15tω])/(15π),

(4Sin[17tω])/(17π),

(4Sin[19tω])/(19π)

正弦波无须展开的.

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