找到你今天要练的题。

f (x) = (x − 10)(x + 13)
The function f is defined by the given equation. For what value of x does f (x) reach its minimum?

The function f (x) =\( \frac{1}{9} \)(x − 7)²  + 3 gives a metal ball’s height above the ground f (x),  in inches,  x seconds after it started moving on a track, where 0 ≤ x ≤  10. Which of the following is the best interpretation of the vertex of the graph of y = f (x) in the xy-plane?

y=0.25x²-7.5x +80.25
The equation gives the estimated stock price y, in dollars, for a certain company x days after the company went public, where 0≤ x ≤20 . Which statement is the best interpretation of (x, y )=(1,73) in this context?

\( x+5=11 \) 
\( y=3x^2+3 \) 
At what point (x, y) do the graphs of the equations in the given system intersect?

An auditorium has seats for 2,600 people. Tickets to attend a show at the auditorium currently cost $8.00. For each $1.00 increase to the ticket price, 100 fewer tickets will be sold. This situation can be modeled by the equation \( y=-100x^2+1,800x+20,800 \), where x represents the increase in ticket price, in dollars, and y represents the revenue, in dollars, from ticket sales. If this equation is graphed in the xy-plane, at what value of x is the maximum of the graph?

An auditorium has seats for 3,000 people. Tickets to attend a show at the auditorium currently cost $8.00. For each $1.00 increase to the ticket price, 100 fewer tickets will be sold. This situation can be modeled by the equation \( y=-100x^2+2,200x+24,000, \)  where x represents the increase in ticket price, in dollars, and y represents the revenue, in dollars, from ticket sales. If this equation is graphed in the xy-plane, at what value of x is the maximum of the graph?

An object is launched from a height of 130 feet above the ground.A quadratic function f models the height above the ground, in feet, of the object t seconds after it is launched. According to the model,2 seconds after the object is launched. it reaches a maximum height of 194 feet above the ground. which equation defines f?

An auditorium has seats for 3200 people. Tickets to attend a show at the auditorium currently cost $8.00. For each $1.00 increase to the ticket price, 100 fewer tickets will be sold. This situation can be modeled by the equation y=-100x²+2400x+25600, where x represents the increase in ticket price, in dollars, and y represents the revenue, in dollars, from ticket sales. If this equation is graphed in the xy-plane, at what value of x is the maximum of the graph?

An auditorium has seats for 3,200 people. Tickets to attend a show at the auditorium currently cost $8.00. For each $1.00 increase to the ticket price, 100 fewer tickets will be sold. This situation can be modeled by the equation y = -100x² +2,400x+25,600, where x represents the increase in ticket price, in dollars, and y represents the revenue, in dollars, from ticket sales. If this equation is graphed in the xy-plane, at what value of x is the maximum of the graph?

An object is launched into the air from ground level.According to a quadratic model,3.8 seconds after the object is launched, it reaches its maximum height of 231.04 feet above ground level. Which equation represents this model, where f(t) is the object's height, in feet, above ground level t seconds after it was launched?

A company developed a plan to set the selling price of a product. The company determined that for a selling price of $150.00, zero products would be sold. For each $2.50 decrease in the selling price, the number of products sold would increase by one. For a revenue of exactly $2,187.50, which of the following could be the number of products sold? (revenue = price × number of products sold)

\( f\left(x\right)=-8x^2+118x \) 
The function \( f \) models the depth below sea level, in meters, of a certain seal x minutes after the seal dives into the water. What is the best interpretation of \( f\left(2\right)=204 \) in this context?