Question 431413
Apparently it seems like the other tutor taught you this...:)


From Euler's formula, {{{e^(i*theta) = cos(theta) + i*sin(theta)}}}. By substituting {{{theta = pi}}} you will obtain {{{e^(i*pi) = -1}}}, {{{e^(i*pi) + 1 = 0}}}. Euler's formula itself is derived using the Maclaurin series for {{{e^x}}}, namely {{{e^x = sum((x^k)/k!, k=0, infinity)}}} (you will learn this sometime in calculus).