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Find [vec(a)vec(b)vec(c )] if vec(a)=vec...

Find `[vec(a)vec(b)vec(c )]` if `vec(a)=vec(i)-2hat(j)+3hat(k), vec(b)=2hat(i)-3hat(j)+hat(k)` and `vec(c )=3hat(i)+hat(j)-2hat(k)`.

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To find the scalar triple product \([ \vec{a} \vec{b} \vec{c} ]\), we will use the determinant of a 3x3 matrix formed by the components of the vectors \(\vec{a}\), \(\vec{b}\), and \(\vec{c}\). ### Given: \[ \vec{a} = \hat{i} - 2\hat{j} + 3\hat{k} \\ \vec{b} = 2\hat{i} - 3\hat{j} + \hat{k} \\ \vec{c} = 3\hat{i} + \hat{j} - 2\hat{k} \] ### Step 1: Write the vectors in component form The vectors can be represented as: - \(\vec{a} = (1, -2, 3)\) - \(\vec{b} = (2, -3, 1)\) - \(\vec{c} = (3, 1, -2)\) ### Step 2: Set up the determinant The scalar triple product can be expressed as the determinant of the following matrix: \[ \begin{vmatrix} 1 & -2 & 3 \\ 2 & -3 & 1 \\ 3 & 1 & -2 \end{vmatrix} \] ### Step 3: Calculate the determinant To calculate the determinant, we can use the formula for a 3x3 determinant: \[ \text{Det} = a(ei - fh) - b(di - fg) + c(dh - eg) \] Where: - \(a = 1\), \(b = -2\), \(c = 3\) - \(d = 2\), \(e = -3\), \(f = 1\) - \(g = 3\), \(h = 1\), \(i = -2\) Calculating each part: 1. \(ei - fh = (-3)(-2) - (1)(1) = 6 - 1 = 5\) 2. \(di - fg = (2)(-2) - (1)(3) = -4 - 3 = -7\) 3. \(dh - eg = (2)(1) - (-3)(3) = 2 + 9 = 11\) Now substituting back into the determinant formula: \[ \text{Det} = 1(5) - (-2)(-7) + 3(11) \] \[ = 5 - 14 + 33 \] \[ = 5 - 14 + 33 = 24 \] ### Final Result: Thus, the value of the scalar triple product \([ \vec{a} \vec{b} \vec{c} ]\) is \(24\). ---
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Find vec(a).(vec(b)xx vec(c )) if : vec(a)=2hat(i)+hat(j)+3hat(k), vec(b)=-hat(i)+2hat(j)+hat(k) and vec(c )=3hat(i)+hat(j)+2hat(k) .

Find [vec(a)vec(b)vec(c)] , when (i) vec(a)=2hat(i)+hat(j)+3hat(k), vec(b)=-hat(i)+2hat(j)+hat(k) and vec(c)=3hat(i)+hat(j)+2hat(k) (ii) vec(a)=2hat(i)-3hat(j)+4hat(k), vec(b)=hat(i)+2hat(j)-hat(k) and vec(c)=3hat(i)-hat(j)+2hat(k) (iii) vec(a) = 2 hat(i)-3hat(j), vec(b)=hat(i)+hat(j)-hat(k) and vec(c)=3hat(i)-hat(k)

Knowledge Check

  • Vector vec(A)=hat(i)+hat(j)-2hat(k) and vec(B)=3hat(i)+3hat(j)-6hat(k) are :

    A
    Parallel
    B
    Antiparallel
    C
    Perpendicular
    D
    at acute angle with each other
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