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Homework Statement
Find the values of x such that the angle between the vectors <2, 1, -1>, and <1, x, 0> is 45 degrees.
Homework Equations
<2, 1, -1> dot <1, x, 0> = 2 + x
|first vector| = (6)0.5
|2nd vector| = (1 + x2)1/2
Angle = cos-1(a dot b)/(|a||b|)
Cosine of 45 is the root of two divided by two.
The Attempt at a Solution
I set (2 + x) divided by 6^0.5 and (1 + x2)^0.5 equal to 1 divided by the root of 2.
I eventually get 2√2 + x√2 = √6√1 + x2
Am I on the right track?