p and q are complex numbers such that |p|=7√2 and |p+q|=12√3 .



On what interval must |q| fall on?



A [7√6/24,[infinity])



B [12√3−7√2,[infinity])



C [12√3+7√2,[infinity])



D [4√6/7,[infinity])

Respuesta :

Answer:

Option B is correct

Step-by-step explanation:

Given: [tex]\left | p \right |=7\sqrt{2}\,,\,\left | p+q \right |=12\sqrt{3}[/tex]

To find: interval on which [tex]\left | q \right |[/tex] must fall

Solution:

[tex]\left | p \right |=7\sqrt{2}\\-7\sqrt{2}\leq p\leq 7\sqrt{2}\,\,(i)[/tex]

[tex]\left | p+q \right |=12\sqrt{3}\\-12\sqrt{3}\leq p+q\leq 12\sqrt{3}\,\,(ii)[/tex]

Subtract (ii) from (i)

[tex]-12\sqrt{3}+7\sqrt{2}\leq p+q-p\leq 12\sqrt{3}-7\sqrt{2}\\-12\sqrt{3}+7\sqrt{2}\leq q\leq 12\sqrt{3}-7\sqrt{2}\\\left | q \right |=12\sqrt{3}-7\sqrt{2}[/tex]

So, [tex]\left | q \right |[/tex] must fall in interval [tex][12\sqrt{3}-7\sqrt{2},\infty)[/tex]

Therefore, option B is correct.