F = factorial(n) %阶乘函数,不仅可以计算整数还可以计算向量矩阵,fractional(1:10);
Gamma函数(gamma):定义为非整数 阶乘;
当n为正整数时,factorial(n) = n*gamma(n);
Limit(f,x,a) %求极限;
极限(f,x,a) % p>
Limit(f,x,a,’right’) %求函数;
双变量求极限:
>>syms x y;
>> f = (exp(x) exp(y))/(cos(x)-sin(y));
> > limit(limit(f,x,0),y,0)
log = ln in matlab;
syms x %是构造符号变量的捷径 .
Diff(f) %求函数f(x)的导数
Diff(f,n) %求函数f(x)的n阶导数
Diff(f,n) %求函数f(x)的n阶导数
p>
Diff(f,x,n) % 计算多元函数f(x,y,…)对x的n阶导数
例如(1) :
syms x;
>> f = 2^x sqrt(x)*log(x);
>> diff(f)
>> p>
ans =log(x)/(2*x^(1/2)) 2^x*log(2) 1/x^(1 /2)
例(2)
>> syms x;
> > f = sin(2*x 3);
>> p>
>> diff(f,2)
ans =-4*sin(2*x 3)
偏导数:
>>syms x,y;
> > f = log(exp(2*(x y^2) (x^2 y ^2) sin(1 x^2));
>>fx = diff(f,x);
>>fy = diff(f,Y);
>> p>
>> fxx = (diff(fx,x));
>> fxy = diff(diff(fx,y))