Two Vectors $\overrightarrow { \mathrm { A } }$ And $\vec { B }$

question 12

Multiple Choice

Two vectors $\overrightarrow { \mathrm { A } }$ and $\vec { B }$ are given by $\overrightarrow { \mathbf { A } } = 5 \hat{ \mathbf { i } } + 6 \hat { \mathbf { j } } + 7 \hat{ \mathbf { k } }$ and $\overrightarrow { \mathbf { B } } = 3 \hat { \mathbf { i } } - 8 \hat { \mathbf { j } } + 2 \hat { \mathbf { k } }$ .If these two vectors are drawn starting at the same point,what is the angle between them?

• A)106\(\degree\)
• B)102\(\degree\)
• C)110\(\degree\)
• D)113\(\degree\)
• E)97\(\degree\)

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Definitions:

REM Sleep

A unique phase of sleep in mammals and birds, characterized by rapid movement of the eyes, low muscle tone throughout the body, and the propensity of the sleeper to dream vividly.

Sleep Spindles

Bursts of oscillatory brain activity visible on an EEG that occur during stage 2 of NREM sleep, believed to play a role in learning and memory consolidation.

N1 Sleep

The initial stage of sleep in a typical sleep cycle, characterized by light sleep from which one can be easily awakened.

Hallucinations

Perceptual experiences that occur without an external stimulus, vivid and clear, with the full force and impact of normal perceptions, not under voluntary control.