document.write( "Question 1192389: A cuboid has a square base of side x cm and its height is (2x+1)cm. Find the approximate increase in its volume when x increases from 10 to 10.05 cm. Hence deduce an approximate value for the volume when
\n" ); document.write( " x = 10.05 cm.
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Algebra.Com's Answer #848997 by CPhill(2189)\"\" \"About 
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**1. Find the Volume of the Cuboid**\r
\n" ); document.write( "\n" ); document.write( "* **Original Volume (V):**
\n" ); document.write( " V = Base Area × Height
\n" ); document.write( " V = x² × (2x + 1)
\n" ); document.write( " When x = 10 cm:
\n" ); document.write( " V = 10² × (2 * 10 + 1)
\n" ); document.write( " V = 100 × 21
\n" ); document.write( " V = 2100 cubic cm\r
\n" ); document.write( "\n" ); document.write( "**2. Approximate Increase in Volume**\r
\n" ); document.write( "\n" ); document.write( "* **Use Differentials:**
\n" ); document.write( " * Volume (V) = x² * (2x + 1) = 2x³ + x²
\n" ); document.write( " * dV/dx = 6x² + 2x
\n" ); document.write( " * Approximate change in volume (dV) ≈ (dV/dx) * dx
\n" ); document.write( " where dx is the change in x (0.05 cm in this case)
\n" ); document.write( " * dV ≈ (6 * 10² + 2 * 10) * 0.05
\n" ); document.write( " * dV ≈ (600 + 20) * 0.05
\n" ); document.write( " * dV ≈ 31 cubic cm\r
\n" ); document.write( "\n" ); document.write( "**3. Approximate Volume when x = 10.05 cm**\r
\n" ); document.write( "\n" ); document.write( "* **Approximate New Volume:**
\n" ); document.write( " * New Volume ≈ Original Volume + Approximate Increase in Volume
\n" ); document.write( " * New Volume ≈ 2100 cubic cm + 31 cubic cm
\n" ); document.write( " * New Volume ≈ 2131 cubic cm\r
\n" ); document.write( "\n" ); document.write( "**Therefore:**\r
\n" ); document.write( "\n" ); document.write( "* **Approximate increase in volume:** 31 cubic cm
\n" ); document.write( "* **Approximate volume when x = 10.05 cm:** 2131 cubic cm\r
\n" ); document.write( "\n" ); document.write( "This method provides an approximation of the volume change using differentials. For a more precise calculation, you could directly calculate the volume at x = 10.05 cm and compare it to the original volume.
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