Solve Study Textbooks Guides

Use app

Login

Question

If a < 0, b > 0, then $a b$ is equal to

A

$- ∣ a ∣ b$

B

$∣ a ∣ b i$

C

$∣ a ∣ b$

D

None of these

Medium

Open in App

Solution

Verified by Toppr

Correct option is B)

$a . b$
$= a b$
However
$a < 0$ and $b > 0$
Hence
$- a > 0$ .
Thus
$a b$ is imaginary.
Hence
$a b$

$= - ∣ a ∣ b$ since $a < 0$ but $∣ a ∣ > 0$

$= i^{2} ∣ a ∣ b$

$= i ∣ a ∣ . b$

Was this answer helpful?

0

0

Similar questions

Evaluate :
$- 25 + 3 - 4 + 2 - 9$

If i = $- 1, t h e n 1 + i^{2} + i^{3} - i^{6} + i^{8}$ is equal to -

Prove that he expression $\frac{( 1 + m ) + i ( 1 - m )}{( 1 + m ) - i ( 1 - m )} - \frac{( 1 - m ) + i ( 1 + m )}{( 1 - m ) - i ( 1 + m )} (m \in R)$ simplifies to 2m.

$- 1 - - 1 - - 1 - . . . \infty =$

This question has multiple correct options

If $z = (i)^{(i)^{(i)}}$ where $i = - 1$ , then |z| is equal to