Recognize vector quantities as having both magnitude and direction. Represent vector quantities by directed line segments, and use appropriate symbols for vectors and their magnitudes (e.g., 𝙫, |𝙫|, ||𝙫||, 𝘷).
Add and subtract vectors. Add vectors end-to-end, component-wise, and by the parallelogram rule. Understand that the magnitude of a sum of two vectors is typically not the sum of the magnitudes. Given two vectors in magnitude and direction form, determine the magnitude and direction of their sum. Understand vector subtraction 𝙫 – 𝙬 as 𝙫 + (–𝙬), where –𝙬 is the additive inverse of 𝙬, with the same magnitude as 𝙬 and pointing in the opposite direction. Represent vector subtraction graphically by connecting the tips in the appropriate order. Perform vector subtraction component-wise.
Multiply a vector by a scalar. Represent scalar multiplication graphically by scaling vectors and possibly reversing their direction; Perform scalar multiplication component-wise, e.g., as 𝘤(𝘷ₓ, 𝘷 subscript 𝘺) = (𝘤𝘷ₓ, 𝘤𝘷 subscript 𝘺). Compute the magnitude of a scalar multiple 𝘤𝙫 using ||𝘤𝙫|| = |𝘤|𝙫. Compute the direction of 𝘤𝙫 knowing that when |𝘤|𝙫 ≠ 0, the direction of 𝘤𝙫 is either along 𝙫 (for 𝘤 > 0) or against 𝙫 (for 𝘤 < 0).