If you click through to the interactive example, you can try it! You'll see that the if the above equations are `q`, then full formula to rotate a vector `v` is `v' = q * v * q^-1`
q = cos(0) + sin(0)*(ai+bj+ck) = 1 + 0 = 1
v' = q * v * q^-1 = 1 * v * 1^-1 = v