For vectors a=(3,2,5) and b=(1,4,2), what is cos theta between them?
Vectors a=(3,2,5) और b=(1,4,2) के बीच angle theta के लिए cos theta क्या है?
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Correct Answer
B. 21 / sqrt(798)
ExplanationStep 1: use a·b=|a||b|cosθ. Step 2: dot=21, |a|^2=38, |b|^2=21, so cosθ=21/sqrt(798). Step 3: tip: dot product is the direct method for angle between vectors.
Step 1: dot product formula a·b=|a||b|cosθ लगाइए। Step 2: dot=21, |a|^2=38, |b|^2=21, इसलिए cosθ=21/sqrt(798)। Step 3: tip: angle between vectors में dot product सबसे direct method है।