表达式3: cosine left parenthesis, 2 pi "f" left parenthesis, "x" , right parenthesis "x" , right parenthesis 有图表。 要进行音频跟踪,按“Alt 键 + T”。cos2πfxx
3
表达式4: cosine left parenthesis, 2 pi Start integral from 0 to "x" , end integral, "f" left parenthesis, "t" , right parenthesis "d" "t" , right parenthesis negative 4 有图表。 要进行音频跟踪,按“Alt 键 + T”。cos2π∫x0ftdt−4