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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 53

In Exercises 53–56, let u = -2i + 3j, v = 6i - j, w = -3i. Find each specified vector or scalar. 4u - (2v - w)

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Identify the given vectors: \( \mathbf{u} = -2\mathbf{i} + 3\mathbf{j} \), \( \mathbf{v} = 6\mathbf{i} - \mathbf{j} \), and \( \mathbf{w} = -3\mathbf{i} \).
Calculate \( 2\mathbf{v} \) by multiplying each component of \( \mathbf{v} \) by 2: \( 2\mathbf{v} = 2(6\mathbf{i} - \mathbf{j}) = 12\mathbf{i} - 2\mathbf{j} \).
Subtract \( \mathbf{w} \) from \( 2\mathbf{v} \): \( 2\mathbf{v} - \mathbf{w} = (12\mathbf{i} - 2\mathbf{j}) - (-3\mathbf{i}) = 12\mathbf{i} - 2\mathbf{j} + 3\mathbf{i} = 15\mathbf{i} - 2\mathbf{j} \).
Calculate \( 4\mathbf{u} \) by multiplying each component of \( \mathbf{u} \) by 4: \( 4\mathbf{u} = 4(-2\mathbf{i} + 3\mathbf{j}) = -8\mathbf{i} + 12\mathbf{j} \).
Subtract \( (2\mathbf{v} - \mathbf{w}) \) from \( 4\mathbf{u} \): \( 4\mathbf{u} - (2\mathbf{v} - \mathbf{w}) = (-8\mathbf{i} + 12\mathbf{j}) - (15\mathbf{i} - 2\mathbf{j}) = -8\mathbf{i} + 12\mathbf{j} - 15\mathbf{i} + 2\mathbf{j} = -23\mathbf{i} + 14\mathbf{j} \).

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