This is true but does not follow from the preceding steps, specifically finding it to be equal to -1. You can obviously find it from i²=-1 but they didn’t show that. I think they tried to equivocate this expression with the answer for eiπ which you can’t do, it doesn’t follow because eiπ and i¹⁰ = ln(-1)¹⁰/pi¹⁰ are different expressions and without external proof, could have different values.
This is true but does not follow from the preceding steps, specifically finding it to be equal to -1. You can obviously find it from i²=-1 but they didn’t show that. I think they tried to equivocate this expression with the answer for eiπ which you can’t do, it doesn’t follow because eiπ and i¹⁰ = ln(-1)¹⁰/pi¹⁰ are different expressions and without external proof, could have different values.