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Vectors (Advanced)

Harder items at competition-adjacent depth.

Phase 2 · JEE

Vectors: core idea

Projection formulas.

Example problem: hint and answer

Volume of tetrahedron vertices (0,0,0),(1,0,0),(0,1,0),(0,0,1)(0,0,0),(1,0,0),(0,1,0),(0,0,1)?

Hint: 16∣scalartriple∣\tfrac16|scalar triple|. Answer: 1/6.

Practice (9 problems — type your answers)

  • 1. Distance from point (0,0,1)(0,0,1) to plane z=0z=0?

  • 2. Angle between planes z=0z=0 and x=0x=0 degrees?

  • 3. Shortest distance between skew lines? For xx-axis and line (0,1,0)+t(0,0,1)(0,1,0)+t(0,0,1): distance?

  • 4. Coplanar: points (0,0,0),(1,0,0),(0,1,0),(1,1,a)(0,0,0),(1,0,0),(0,1,0),(1,1,a) for which aa?

  • 5. Reflect (0,0,1)(0,0,1) across plane z=0z=0: zz-coordinate?

  • 6. Area of triangle (0,0,0),(2,0,0),(0,2,0)(0,0,0),(2,0,0),(0,2,0)?

  • 7. If a⋅b=0\mathbf a\cdot\mathbf b=0 and ∣a∣=∣b∣=2|a|=|b|=2, ∣a×b∣|a\times b|?

  • 8. Line through (1,1,1)(1,1,1) direction ⟨1,0,0⟩\langle1,0,0\rangle meets plane x=3x=3 at x=x=?

  • 9. Lagrange: ∣a×b∣2+∣a⋅b∣2|a\times b|^2+|a\cdot b|^2 for unit vectors equals?

Vectors Practice Problems — Advanced