A gemcutter wants to trim a gemstone that is approximately a regular octahedron with sides measured in millimeters (mm). She will remove imperfections by reducing the length of each side by x mm. The approximate new surface area is given in mm2 by the function: S(x)=3.4(56.25−15x+x2)What is the current length of each side?
Q. A gemcutter wants to trim a gemstone that is approximately a regular octahedron with sides measured in millimeters (mm). She will remove imperfections by reducing the length of each side by x mm. The approximate new surface area is given in mm2 by the function: S(x)=3.4(56.25−15x+x2)What is the current length of each side?
Identify Function: Identify the original function for the surface area of the gemstone.The function given is S(x)=3.4(56.25−15x+x2). This function represents the new surface area after x mm is trimmed from each side of the gemstone. To find the current length of each side, we need to consider the value of x that has not been trimmed yet, which means we need to find the value when x=0.
Substitute x=0: Substitute x=0 into the function to find the surface area of the gemstone before trimming.S(0)=3.4(56.25−15(0)+02)S(0)=3.4(56.25)
Calculate Original Area: Calculate the surface area of the original gemstone.S(0)=3.4×56.25S(0)=191.25mm2
Surface Area Formula: Recognize that the surface area of a regular octahedron is given by the formula S=23a2, where a is the length of a side. We need to equate this to the original surface area we found to solve for a.191.25=23a2
Isolate a2: Divide both sides of the equation by 2×3 to isolate a2.a2=2×3191.25
Calculate a2: Calculate the value of a2. a2=2×3191.25 a2=2×1.732191.25 a2=3.464191.25 a2=55.21 (rounded to two decimal places)
Solve for a: Take the square root of both sides to solve for a.a=55.21a≈7.43mm
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