Question

Given that r 1 = 3 i + 5 j r1=3i+5j , r 2 = д љ Н 4 i + 19 j r2=дљН4i+19j. Find the modulus of 5 r 1 д љ Н r 2 5r1дљН

Answer 1

The values in the question are mixed-up.

But there are two vectors given in the question named r1 & r2.

r1 = 3i + 5j

r2 = 4i + 19j

We have to find the modulus of 5 r1 + 3 r2

So we have

5 r1 + 3 r2 = 5 (3i + 5j) + 3 ( 4i + 19j )

                = 15i + 25j + 12i + 57j

5 r1 + 3 r2 = 27i + 82j

Now modulus of 5 r1 + 3 r2 = $\sqrt{x} 27^{2} + 82^{2}$

Now modulus of 5 r1 + 3 r2 = 86.33