I want to convert the following euler formula in trigonometric form
there is a command called ComplexExpand
But it will produce the undesired results
(1)
the instructions below the picture will differentiate the equation and then expand it
it will produce the undesired result
f2 = D[f1[t],t] // ComplexExpand
(2)
Desired result
r3'[t]*( Cos[q3[t]] + I Sin[q3[t]] )-
r1(q1)'[t]*( Cos[q1[t]] + I Sin[q1[t]] )+
r2(q2)'[t]*( Cos[q2[t]] + I Sin[q2[t]] )+
r3[t](q3)'[t]*( Cos[q3[t]] + I Sin[q3[t]] )