用Octave计算导数基本公式（7）

三角函数求导公式（3）

\( ({\rm tan} x )'={\rm sec}^2 x \)

function [text_result, numeric_result] = func24()
    pkg load symbolic;
    x = sym('x');
    question = tan(x);
    lim = diff(question, x);
    text_result = ["\n", disp(lim)];
    numeric_result = eval(lim);
endfunction

>> [text_result, numeric_result] = func24()
text_result =
       2
    tan (x) + 1

numeric_result = (sym)

       2
    tan (x) + 1