Unit Test — Unit test Answers

0 verified answers2 views

Free Preview

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (–1 + i) + (21 + 5i)?

(–1 + i) + (21 + 5i) + 0

–1 + (i + 21) + 5i

(–1 + 21) + (i + 5i)

–(1 – i) + (21 + 5i)

Free Preview

Which function is a quadratic function?

y – 3x2 = 3(x2 + 5) + 1

y2 – 7x = 2(x2 + 6) + 7

y – 2x2 = 6(x3 + 5) – 4

y – 5x = 4(x + 5) + 9

Which equation has a graph that lies entirely above the x-axis?

y = –(x + 7)2 + 7

y = (x – 7)2 – 7

y = (x – 7)2 + 7

y = (x – 7)2

Which values of x and y would make the following expression represent a real number?(4 + 5i)(x + yi)

x = 4, y = 5

x = –4, y = 0

x = 4, y = –5

x = 0, y = 5

What is the solution set of the quadratic inequality

Option

A soccer ball is kicked upward from a hill and then falls to the ground. The height, in feet, of the ball after t sec is modeled by the function h(t) = –16t2 + 26t +12. What is the initial height of the ball?

–16 ft

–12 ft

12 ft

22 ft

In which quadrant is the number 6 – 8i located on the complex plane?

III

Which statement about the following equation is true?2x2 – 9x + 2 = –1

The discriminant is less than 0, so there are two real roots.

The discriminant is less than 0, so there are two complex roots.

The discriminant is greater than 0, so there are two real roots.

The discriminant is greater than 0, so there are two complex roots.

Use the zero product property to find the solutions to the equation x2 + x – 30 = 12.

x = –7 or x = 6

x = –7 or x = –6

x = –6 or x = 7

x = 6 or x = 7

Which equation is y = 9x2 + 9x – 1 rewritten in vertex form?

y = 9 (x + one-half) squared minus thirteen-fourths

y = 9 (x + one-half) squared minus 1

y = 9 (x + one-half) squared + five-fourths

y = 9 (x + one-half) squared minus five-fourths

The height of a stuntperson jumping off a building that is 20 m high is modeled by the equation h = 20 – 5t2, where t is the time in seconds. A high-speed camera is ready to film the person between 15 m and 10 m above the ground. For which interval of time should the camera film the person?

Option

t < 2

What is the value of the expression i 0 × i 1 × i 2 × i 3 × i 4?

–1

–i

If x2 + mx + m is a perfect-square trinomial, which equation must be true?

x2 + mx + m = (x – 1)2

x2 + mx + m = (x + 1)2

x2 + mx + m = (x + 2)2

x2 + mx + m = (x + 4)2

The length of a rectangle is three times the width. The area of the rectangle is 108 sq in. What is the width of the rectangle?

6 in.

9 in.

12 in.

36 in.

A rectangular pan has a length that is the width. The total area of the pan is 432 in.2. What is the width of the cake pan?A = lw

10.4 in.

13.9 in.

18 in.

24 in.

Using the quadratic formula to solve 4x2 – 3x + 9 = 2x + 1, what are the values of x?

StartRoot 1 plus-or-minus StartRoot 159 EndRoot i Over 8 EndFraction

StartRoot 5 plus-or-minus StartRoot 153 EndRoot i Over 8 EndFraction

StartRoot 5 plus-or-minus StartRoot 103 EndRoot i Over 8 EndFraction

StartRoot 1 plus-or-minus StartRoot 153 EndRoot Over 8 EndFraction

Which equation is the inverse of ?

y = one-sixth x squared minus four-thirds x + StartFraction 43 Over 9 EndFraction

y = 4 plus-or-minus StartRoot 6 x minus StartFraction 34 Over 3 EndFraction EndRoot

y = negative 4 plus-or-minus StartRoot 6 x minus StartFraction 34 Over 3 EndFraction EndRoot

negative (x minus 4) squared minus two-thirds = negative 6 y + 12

Solve for in the equation .

x = 6 plus-or-minus 3 StartRoot 10 EndRoot

x = 6 plus-or-minus 2 StartRoot 7 EndRoot

x = 12 plus-or-minus 3 StartRoot 22 EndRoot

x = 12 plus-or-minus 3 StartRoot 10 EndRoot

The graph below shows the height of a projectile t seconds after it is launched. If acceleration due to gravity is –16 ft/s2, which equation models the height of the projectile correctly?h(t) = at2 + vt + h0