Question

Given that p=9i+12j and q=-6i-8j. Evaluate |p-q|-{|p|-|q|}

Answer 1

Answer:

$|p-q|-(|p|-|q|) = 20$

Step-by-step explanation:

First let's find the value of 'p-q':

$p - q = 9i + 12j - (-6i - 8j)\\p - q = 9i + 12j + 6i + 8j\\p - q = 15i + 20j$

To find |p-q| (module of 'p-q'), we can use the formula:

$|ai + bj| = \sqrt{a^{2}+b^{2}}$

Where 'a' is the coefficient of 'i' and 'b' is the coefficient of 'j'

So we have:

$|p - q| = |15i + 20j| = \sqrt{15^{2}+20^{2}} = 25$

Now, we need to find the module of p and the module of q:$|p| = |9i + 12j| = \sqrt{9^{2}+12^{2}} = 15$

$|q| = |-6i - 8j| = \sqrt{(-6)^{2}+(-8)^{2}} = 10$

Then, evaluating |p-q|-{|p|-|q|}, we have:

$|p-q|-(|p|-|q|) = 25 - (15 - 10) = 25 - 5 = 20$