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Question : An object is thrown upward with an initial velocity : 2163528

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Find the vertex of the parabola.

21) f(x) = x^{2} - 8x

A) 4

B) -16

C) -4

D) 16

Find the maximum y-value on the graph of y = f(x).

22) f(x) = -x^{2} + 2x + 1

A) 1

B) -1

C) -2

D) 2

23) f(x) = 4x - x^{2}

A) -4

B) 4

C) 2

D) -2

Graph f(x).

24) f(x) = -2x^{2}

A)

B)

C)

D)

25) f(x) = (1/5)x^{2}

A)

B)

C)

D)

26) f(x) = - (1/3)x^{2}

A)

B)

C)

D)

Compare the graph of f(x) with the graph of y = x^{2}.

27) f(x) = -x^{2}

A) Wider

B) Narrower

C) Reflected across the x-axis

D) Reflected across the y-axis

28) f(x) = -4x^{2}

A) Reflected across the y-axis and wider

B) Reflected across the x-axis and wider

C) Reflected across the x-axis and narrower

D) Reflected across the y-axis and narrower

29) f(x) = - (5/4)x^{2}

A) Reflected across the x-axis and narrower

B) Reflected across the y-axis and wider

C) Reflected across the y-axis and narrower

D) Reflected across the x-axis and wider

30) f(x) = 5x^{2}

A) Narrower

B) Reflected across the x-axis and wider

C) Wider

D) Reflected across the x-axis and narrower

31) f(x) = (1/4)x^{2}

A) Reflected across the x-axis and wider

B) Narrower

C) Wider

D) Reflected across the x-axis and narrower

32) f(x) = - (1/3)x^{2}

A) Reflected across the x-axis and wider

B) Narrower

C) Wider

D) Reflected across the x-axis and narrower

33) f(x) = - (3/4)x^{2}

A) Reflected across the y-axis and narrower

B) Reflected across the y-axis and wider

C) Reflected across the x-axis and narrower

D) Reflected across the x-axis and wider

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

Determine whether the graph of f opens upward or downward and whether the graph is wider, narrower, or the same as the graph of y = x^{2}. Find the axis of symmetry and the vertex. Find the y-intercept and any x-intercepts. Sketch a graph of f.

34) f(x) = x^{2} - 4x - 5

35) f(x) = - (1/2)x^{2} - x + 4

36) f(x) = 3x - x^{2}

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Solve the problem.

37) John owns a hotdog stand. He has found that his profit is represented by the equation P = -x^{2} + 80x + 85, with P being profits and x the number of hotdogs. How many hotdogs must he sell to earn the most profit?

A) 22 hotdogs

B) 40 hotdogs

C) 45 hotdogs

D) 41 hotdogs

38) Bob owns a watch repair shop. He has found that the cost of operating his shop is given by c = 3x^{2} - 288x + 70, where c is cost and x is the number of watches repaired. How many watches must he repair to have the lowest cost?

A) 48 watches

B) 35 watches

C) 70 watches

D) 30 watches

39) A projectile is thrown upward so that its distance above the ground after t seconds is h = -13t^{2} + 468t. After how many seconds does it reach its maximum height?

A) 27 sec

B) 36 sec

C) 9 sec

D) 18 sec

40) An object is thrown upward with an initial velocity of 15 ft per second. Its height is given by h = -15t^{2} + 60t at time t seconds. After how many seconds does it hit the ground?

A) 2 sec

B) 6 sec

C) 4 sec

D) 5 sec