It appears that the Pythagorean theorem can be applied to this problem (distance to shadow)² = (height of building)² + (length of shadow)² (38 m)² = (height of building)² + (28 m)² 660 m² = (height of building)² Then the height of the building is height of building = √660 m ≈ 25.7 m
No profit means P(x)=0: x³-4x²+3x-12=0 factor by regrouping: x²(x-4)+3(x-4)=0 take out (x-4): (x-4)(x²+3)=0 x=4 or x²=-3 x² is not a negative number, so x=4 is the only answer.
