Question

Question #6cf2e

Answer 1

See below.

Explanation:

sin(a+b) = sina cos b+cosa sinb# or

`sin(x+i pi) = sinx cos(i pi)+cosx sin(ipi)`

but

`cos(i pi) =cosh(pi)`
`sin(i pi) = i sinh(pi)`

then finally

`sin(x+i pi) = sinx cosh pi +i cosx sinh pi`