Question

Find a.b. a=2i+j, b=i-j+k

Answer 1

Answer:

$a.b = 1$

Step-by-step explanation:

We are given the following in the question:

$a=2i+j\\b=i-j+k$

We have to find the dot product.

Formula:

$a = x_1i + x_2j + x_3k\\b = y_1i + y_2j + y_3k\\a.b = x_1y_1 + x_2y_2 + x_3y_3$

Putting the corresponding values we get,

$a.b = (2.1) + (1.-1) + (0.1)\\= 2-1+0\\=1$

$a.b = 1$