Question

求第一步到第二步的详细过程，我怎么算都算不出

Answer 1

{a*[sin(θ/3)]^3}' = a*{[sin(θ/3)]^3}' = a*3*[sin(θ/3)]^2 * [sin(θ/3)]' = a*3*[sin(θ/3)]^2 * (1/3)*cos(θ/3)
= a*[sin(θ/3)]^2 * cos(θ/3)
所以：{a*[sin(θ/3)]^3}^2 + {{a*[sin(θ/3)]^3}' }^2
= {a*[sin(θ/3)]^2}^2 * [sin(θ/3)]^2+ {a*[sin(θ/3)]^2}^2 * [cos(θ/3)]^2
= {a*[sin(θ/3)]^2}^2 * {[sin(θ/3)]^2 + [cos(θ/3)]^2}
= {a*[sin(θ/3)]^2}^2

追问

所以上面

求导那里不明白

追答

上面用到了：
(x^3)' = 2*x^2
(sinx)' = cosx
[sin(x/a)]' = cos(x/a) * (x/a)' = (1/a)*cos(x/a)
{[f(x)]^3}' = 3*[f(x)]^2 * f'(x)

Answer 2

这是指数运算的问题 a^m=b，那么a=b^(1/m)

追问

????