Question

Let a = (-3,4) and v = (4,-5).
If a + b = v. find b.

Answer 1

b = (7, -9)

Explanation:

Let a = (-3,4) and v = (4,-5).

If a + b = v. find b.

performing the addition of the vectors would mean that we add corresponding coordinates.

so

let b = (x, y)

then a + b = (-3, 4) + (x, y) = (-3 + x, 4+y) = v = (4, -5)

-3 + x = 4

4 + y = -5

x = 7

y = -5 - 4 = -9

so b = (7, -9)