The amount of money that a local charity earns by selling T-shirts at a mall depends on the price of each T-shirt. The monthly profit, 𝑦, in dollars is given by the quadratic equation 𝑦 = −35𝑥2 + 1250𝑥 − 6500 where 𝑥 represents the price of each T-shirt. Determine the vertex of the parabola

1 answer

To find the vertex of the parabola, we need to find the value of 𝑥 that gives the maximum value of 𝑦. One way to do this is by using the formula 𝑥 = −𝑏/2𝑎, where 𝑏 is the coefficient of the linear term and 𝑎 is the coefficient of the quadratic term.

In this case, 𝑎 = −35 and 𝑏 = 1250. Therefore,

𝑥 = −1250/2(−35) = 1250/70 ≈ 17.86

This means that the maximum profit is obtained when the price of each T-shirt is approximately $17.86.

To find the maximum profit, we can substitute this value of 𝑥 into the equation 𝑦 = −35𝑥2 + 1250𝑥 − 6500:

𝑦 = −35(17.86)2 + 1250(17.86) − 6500 ≈ $11,056.96

Therefore, the vertex of the parabola is approximately (17.86, 11,056.96).