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旧 2009-04-27, 18:44   #3
mathjiang
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注册日期: 2008-01-02
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默认 回复: 询问下一个matlab求一阶导数的问题

>>syms theta a b c d w h;
>>f=( ( theta*(1-d)/(theta*d-d)+1 ) *w-c )*a*( a*(1+b)/ ( 2*h*(theta-1) ) )^(b/1-b)* ( (theta-1)*d/theta ) ^ (theta /(1-b) ) *w^ ( (1-b)/(b- theta) );
>>pretty(f);
>>foverd = diff(f,d)
>>foverd=
(a*w*(theta/(d - d*theta) + (theta*(d - 1)*(theta - 1))/(d - d*theta)^2))/(w^((b - 1)/(b - theta))*((d*(theta - 1))/theta)^(theta/(b - 1))) + (a*(theta - 1)*(c - w*((theta*(d - 1))/(d - d*theta) + 1)))/(w^((b - 1)/(b - theta))*(b - 1)*((d*(theta - 1))/theta)^(theta/(b - 1) + 1))
注:计算有点儿慢。
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