43.6k views
2 votes
Find a b. 7√6 |a| = 7, |b|= √6, the angle between a and b is 45° X

1 Answer

5 votes

To find the value of b, we can use the given information:

|a| = 7

|b| = √6

The angle between a and b is 45°.

We know that the dot product of two vectors a and b is given by:

a · b = |a| |b| cos(θ)

where θ is the angle between a and b.

In this case, we have:

a · b = 7 √6 cos(45°)

Since cos(45°) = √2 / 2, we can substitute the values:

7 √6 cos(45°) = 7 √6 (√2 / 2) = 7√12 / 2

We also know that a · b = |a| |b|, so we can set up the equation:

7√12 / 2 = 7 √6 |b|

Now, solving for |b|:

|b| = (7√12 / 2) / (7 √6)

Simplifying the expression:

|b| = √2 / 2

Therefore, the value of b is √2 / 2.

Related questions