Browse Questions

# Express the following in the form of $\;a+bi : (-i) \; (2i)\;(-\large\frac{1}{8}i)^{3}$

$(a)\;\large\frac{1}{256} i\qquad(b)\;\large\frac{3}{256}i \qquad(c)\;\large\frac{5}{256} i \qquad(d)\;\large\frac{5}{3} i$

Answer : $\;\large\frac{1}{256} i$
Explanation :
$(-i) \; (2i)\;(-\large\frac{1}{8}i)^{3}= 2 \times \large\frac{1}{8 \times 8 \times 8} \times i^{5}$
$= \large\frac{1}{256} (i^{2})^{2}\;i$
$=\large\frac{1}{256} i\;.$