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Given v=2i−j and w=3i+8j​, find the angle between v and w.

User Ivo Leko
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Final answer:

To find the angle between vectors v and w, we can use the dot product formula: v&w = |v||w|cos(theta). The angle between vectors v and w is approximately 126.06°.

Step-by-step explanation:

To find the angle between vectors v and w, we can use the dot product formula:
v&w = |v||w|cos(theta)

where |v| and |w| are the magnitudes of vectors v and w, and theta is the angle between them.

The dot product of vectors v and w is:
v&w = (2)(3) + (-1)(8) = -2

The magnitudes of vectors v and w are:

|v| = sqrt((2)^2 + (-1)^2) = sqrt(5)
|w| = sqrt((3)^2 + (8)^2) = sqrt(73)

Substituting the values into the formula:

-2 = (sqrt(5))(sqrt(73))cos(theta)

Solving for cos(theta):

cos(theta) = -2/(sqrt(5))(sqrt(73))

Using a calculator to find the inverse cosine of cos(theta), we get:

theta = 126.06°

Therefore, the angle between vectors v and w is approximately 126.06°.

User Walid Ammar
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