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
![](/c/portal/getImageAttachment?filename=5.jpg&userId=231129)
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]] )