The magnitude of two vectors is given. However, the angle included between them is not specified. The given sum of the vectors will provide us the cosine of the unknown angle. Hence, by applying the formula for vector addition, we get |
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=10√3| √a2+b2+2abcosθ=10√3 a2+b2+2abcosθ=300 49+121+2(77)cosθ=300 154cosθ=130...(1) Hence the magnitude of the subtraction of the two vectors is given by |