Question

There are two vectors à and b, with an angle between them. Then the dot product of them is A. a. b = ab cos B. a b = (a + b) cos C. a. b = ab sino D.. b = (a + b) sino

Answer 1

`a.b=|a||b|\ cos\theta`

Step-by-step explanation:

Let a and b are two vectors such that
`\theta` is the angle between them. Dot product is also known as scalar product. It is used to find the angle between two vectors such that,

`a.b=|a||b|\ cos\theta`

`\theta` is the angle between a and b. It can be calculated as :

`\theta=cos^(-1)((a.b)/(|a||b|))`

`|a|\ and\ |b|` are the magnitude of vectors a and b such that :

`|a|=√(x^2+y^2+z^2)` if a = xi +yj +zk

and

`|b|=√(p^2+q^2+r^2)` if a = pi +qj +rk

So, the correct option is (a). Hence, this is the required solution.