Given vectors a = (2, x, 0), b = (1, 0, −1), c = (5, −9, 3), and let P(2, 1, −1) be

[Niamh]

Given vectors a = (2, x, 0), b = (1, 0, −1), c = (5, −9, 3), and let P(2, 1, −1) be

Hello,
Could someone please help with this question? I don't even know where to start.

Given vectors a = (2, x, 0), b = (1, 0, −1) and c = (5, −9, 3), and let P(2, 1, −1)be a point.1. Find the value of x in a such that the angle between a and b is π/4

 

[Ishuda]

Hello,
Could someone please help with this question? I don't even know where to start.

Given vectors a = (2, x, 0), b = (1, 0, −1) and c = (5, −9, 3), and let P(2, 1, −1)be a point.1. Find the value of x in a such that the angle between a and b is π/4

Do you know what the dot and cross products of vectors represent? See
https://duckduckgo.com/?q=dot+cross+products&t=lm&ia=web