The teacher will be very surprised to see your correct solution 😉
-i2*sin(z) - cos(z) = 5
sum
/ / ___________ \\ / / ___________ \\ / / ___________\\ / / ___________\\
| | / 2 || | | / 2 || | | / 2 || | | / 2 ||
| | \/ -24 + i2 i2|| | | \/ -24 + i2 i2|| | |i2 \/ -24 + i2 || | |i2 \/ -24 + i2 ||
- 2*re|atan|- -------------- + --|| - 2*I*im|atan|- -------------- + --|| + - 2*re|atan|-- + --------------|| - 2*I*im|atan|-- + --------------||
\ \ 4 4 // \ \ 4 4 // \ \4 4 // \ \4 4 //
=
/ / ___________ \\ / / ___________\\ / / ___________ \\ / / ___________\\
| | / 2 || | | / 2 || | | / 2 || | | / 2 ||
| | \/ -24 + i2 i2|| | |i2 \/ -24 + i2 || | | \/ -24 + i2 i2|| | |i2 \/ -24 + i2 ||
- 2*re|atan|- -------------- + --|| - 2*re|atan|-- + --------------|| - 2*I*im|atan|- -------------- + --|| - 2*I*im|atan|-- + --------------||
\ \ 4 4 // \ \4 4 // \ \ 4 4 // \ \4 4 //
product
/ / / ___________ \\ / / ___________ \\\ / / / ___________\\ / / ___________\\\ | | | / 2 || | | / 2 ||| | | | / 2 || | | / 2 ||| | | | \/ -24 + i2 i2|| | | \/ -24 + i2 i2||| | | |i2 \/ -24 + i2 || | |i2 \/ -24 + i2 ||| |- 2*re|atan|- -------------- + --|| - 2*I*im|atan|- -------------- + --|||*|- 2*re|atan|-- + --------------|| - 2*I*im|atan|-- + --------------||| \ \ \ 4 4 // \ \ 4 4 /// \ \ \4 4 // \ \4 4 ///
=
/ / / ___________ \\ / / ___________ \\\ / / / ___________\\ / / ___________\\\ | | | / 2 || | | / 2 ||| | | | / 2 || | | / 2 ||| | | | \/ -24 + i2 i2|| | | \/ -24 + i2 i2||| | | |i2 \/ -24 + i2 || | |i2 \/ -24 + i2 ||| 4*|I*im|atan|- -------------- + --|| + re|atan|- -------------- + --|||*|I*im|atan|-- + --------------|| + re|atan|-- + --------------||| \ \ \ 4 4 // \ \ 4 4 /// \ \ \4 4 // \ \4 4 ///
4*(i*im(atan(-sqrt(-24 + i2^2)/4 + i2/4)) + re(atan(-sqrt(-24 + i2^2)/4 + i2/4)))*(i*im(atan(i2/4 + sqrt(-24 + i2^2)/4)) + re(atan(i2/4 + sqrt(-24 + i2^2)/4)))
/ / ___________ \\ / / ___________ \\
| | / 2 || | | / 2 ||
| | \/ -24 + i2 i2|| | | \/ -24 + i2 i2||
z1 = - 2*re|atan|- -------------- + --|| - 2*I*im|atan|- -------------- + --||
\ \ 4 4 // \ \ 4 4 //
/ / ___________\\ / / ___________\\
| | / 2 || | | / 2 ||
| |i2 \/ -24 + i2 || | |i2 \/ -24 + i2 ||
z2 = - 2*re|atan|-- + --------------|| - 2*I*im|atan|-- + --------------||
\ \4 4 // \ \4 4 //
z2 = -2*re(atan(i2/4 + sqrt(i2^2 - 24)/4)) - 2*i*im(atan(i2/4 + sqrt(i2^2 - 24)/4))