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Ch. 4 - Laws of Sines and Cosines; Vectors
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601Non è quello che usi tu?Cambia libro di testo
Capitolo 4, Problema 44

In Exercises 39–46, find the unit vector that has the same direction as the vector v.


v = 4i - 2j

Guida verificata passo dopo passo
1
Identify the given vector \( \mathbf{v} = 4\mathbf{i} - 2\mathbf{j} \). This means the vector has components \( (4, -2) \).
Calculate the magnitude (length) of the vector \( \mathbf{v} \) using the formula: \[ \|\mathbf{v}\| = \sqrt{(4)^2 + (-2)^2} \]
Simplify the expression under the square root to find the magnitude: \[ \|\mathbf{v}\| = \sqrt{16 + 4} \]
Find the unit vector \( \mathbf{u} \) in the same direction as \( \mathbf{v} \) by dividing each component of \( \mathbf{v} \) by its magnitude: \[ \mathbf{u} = \left( \frac{4}{\|\mathbf{v}\|}, \frac{-2}{\|\mathbf{v}\|} \right) \]
Express the unit vector in terms of the standard unit vectors \( \mathbf{i} \) and \( \mathbf{j} \): \[ \mathbf{u} = \frac{4}{\|\mathbf{v}\|} \mathbf{i} - \frac{2}{\|\mathbf{v}\|} \mathbf{j} \]

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