sin^2(t/2)的导数是多少?是2sin(t/2)cos(t/2)(1/2)还是2cos(t/2)(1/2)?原公式是：A(t)=W(t)-R(t)+1200=95((t)^(1/2))(sin^2(t/6))-275(sin^2(t/3))+1200A'(t)=

Question

sin^2(t/2)的导数是多少?
是 2sin(t/2)cos(t/2)(1/2)
还是 2cos(t/2)(1/2)?
原公式是：
A(t) = W(t) - R(t) + 1200
= 95((t)^(1/2))(sin^2(t/6)) - 275(sin^2(t/3)) + 1200
A'(t) =

Answer 1

[sin^2(t/2)]'=2sin(t/2)[sin(t/2)]'=2sin(t/2)cos(t/2)(t/2)'=sin(t/2)cos(t/2)或者化简为(sint)/2