展开 cos(t)h(t-7)

解答

展开

cos (t) h (t - 7)

t h cos (t) - 7 h cos (t)

求解步骤

cos (t) h (t - 7)

= h cos (t) (t - 7)

使用分配律:

a (b - c) = ab - a c

h cos (t) (t - 7) = h cos (t) t - h cos (t) \cdot 7

= h cos (t) t - h cos (t) \cdot 7

= t h cos (t) - 7 h cos (t)

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