what is magnitude of −3i?

Relevance
• 5 months ago

The magnitude is 3.

• 5 months ago

√(0^2 + (-3)^2) =

√(0 + 9) =

√9 =

3

• Como
Lv 7
5 months ago

-

Magnitude is 3

• JOHN
Lv 7
5 months ago

|-3i| = |-3| x |i| = 3 x 1 = 3.

• 5 months ago

The magnitude is '3' usuallu written as |3|.

• Anonymous
5 months ago

(-3)^2 = 9. Don't listen to the idiots who says it's 3.

• roderick_young
Lv 7
5 months agoReport

The first equation is true, but the "magnitude" of a vector is the absolute value of its length, so 3 is actually correct.

• 5 months ago

i is the square root of -1. so you'll have to square both of these. In this example: -3*-3 =9 and sqrt(-1)*sqrt(-1) =-1 . So now take 9*-1 to get a final answer of -9

• 5 months ago

Remember:

|a + bi| = √(a² + b²)

In this case, a=0, b=-3

|-3i| = √[(-3)²]

= √9

= 3

Of course if you think of it as the distance from the origin (0,0i) to (0,-3i) on the complex plane, it's obviously just 3, as confirmed by the formula.

• 5 months ago

It is just 3.

Use pythagoras to find the hypotenuse and ie. the longest side which is the magnitude when you have numbers in both vertical and horizontal components, like -3i+2j.

Also the magnitude is just the positive value of the length of the line/vector, just thought i'd mention.