GATE 2023 MA – Question 31

Calculus · Vector Calculus · 1 mark · Numerical answer

The portion of z=2x+2y−100 inside x²+y²=1 has surface area απ. Find α.

Show answer and explanation

Correct answer: 3 to 3

Explanation

For the graph, dS=√(1+z_x²+z_y²)dxdy=√9 dxdy=3dxdy. Its projection is the unit disk of area π. Surface area=3π, so **α=3**.

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