Let ∣ a ∣ = 4 , ∣ b ∣ = 1 , and b × α + a = α . If the projection of α along b is 3, find the projection of α along a .

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TestHub · Accepted Answer

Dotting with b gives a dot b = 3. Taking b cross the equation and using |b|=1 gives alpha=(3b+a+b cross a)/2. Hence the scalar projection on a is alpha dot a/|a|=(3a dot b+|a|^2)/8=25/8=3.125.

Mathematics - Vector Question with Solution | TestHub

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