확장 cos(2t)[h(t-pi/2)]

해법

확장

cos (2 t) [h (t - \frac{π}{2})]

t h cos (2 t) - \frac{πh cos ( 2 t )}{2}

솔루션 단계

cos (2 t) (h (t - \frac{π}{2}))

괄호 제거:

(a) = a

= cos (2 t) h (t - \frac{π}{2})

= h cos (2 t) (t - \frac{π}{2})

분배 법칙 적용:

a (b - c) = ab - a c

a = cos (2 t) h, b = t, c = \frac{π}{2}

= cos (2 t) h t - cos (2 t) h \frac{π}{2}

= t h cos (2 t) - \frac{π}{2} h cos (2 t)

\frac{π}{2} h cos (2 t) = \frac{πh cos ( 2 t )}{2}

= t h cos (2 t) - \frac{πh cos ( 2 t )}{2}