Cut Safe company manufactures scissors. The company uses the function P(s)=−25s2+250s−400 to model its profit, where P(x) is the profit in thousands of dollars, and x is the number of scissors sold in tens of thousands. What is the least number of scissors the company needs to sell to break even?
Q. Cut Safe company manufactures scissors. The company uses the function P(s)=−25s2+250s−400 to model its profit, where P(x) is the profit in thousands of dollars, and x is the number of scissors sold in tens of thousands. What is the least number of scissors the company needs to sell to break even?
Identify Break-Even Points: Identify the break-even points.The break-even points occur when the profit P(s) is equal to zero.So, we need to solve the equation −25s2+250s−400=0 for s.
Factor Quadratic Equation: Factor the quadratic equation if possible.The quadratic equation −25s2+250s−400=0 can be factored by finding two numbers that multiply to −25×−400 and add up to 250. However, it's not immediately clear what those numbers are, so we might need to use the quadratic formula instead.
Use Quadratic Formula: Use the quadratic formula to find the roots of the equation.The quadratic formula is s=2a−b±b2−4ac, where a=−25, b=250, and c=−400.
Calculate Discriminant: Calculate the discriminant b2−4ac.Discriminant = b2−4ac=(250)2−4(−25)(−400)=62500−40000=22500.
Calculate Square Root: Calculate the square root of the discriminant.22500=150.
Apply Quadratic Formula: Apply the quadratic formula to find the values of s.s=2⋅−25−250±150.
Calculate Values of s: Calculate the two possible values for s.s1=−50−250+150=−50−100=2.s2=−50−250−150=−50−400=8.
Determine Least Scissors: Determine the least number of scissors to break even.Since we are looking for the least number of scissors, we choose the smaller positive root, which is s=2.However, since s represents tens of thousands of scissors, we need to multiply by 10,000 to find the actual number of scissors.
Calculate Least Scissors: Calculate the least number of scissors to break even in actual numbers.Least number of scissors = s×10,000=2×10,000=20,000.
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