Algebra II : Algebra II

Study concepts, example questions & explanations for Algebra II

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Example Questions

Example Question #38 : Function Notation

Determine \displaystyle f(\frac{1}{3}) if \displaystyle f(x)= \frac{1}{2x}.

Possible Answers:

\displaystyle \frac{3}{2}

\displaystyle \frac{3}{7}

\displaystyle \frac{1}{6}

\displaystyle \frac{7}{3}

\displaystyle 6

Correct answer:

\displaystyle \frac{3}{2}

Explanation:

To determine the output of \displaystyle f(x), substitute the value of \displaystyle \frac{1}{3} as a replacement of \displaystyle x.

\displaystyle f(\frac{1}{3})= \frac{1}{2(\frac{1}{3})} = \frac{1}{\frac{2}{3}}

Rewrite the complex fraction using a division sign.

\displaystyle 1\div \frac{2}{3}

Take the reciprocal of the second term and change the division sign to a multiplication sign.

\displaystyle 1\div \frac{2}{3} = 1\times \frac{3}{2}

The answer is:  \displaystyle \frac{3}{2}

Example Question #161 : Introduction To Functions

Determine \displaystyle f(g(3)) if \displaystyle f(x) = 3 and \displaystyle g(x)=3x.

Possible Answers:

\displaystyle 9

\displaystyle 6

\displaystyle 27

\displaystyle 3

\displaystyle 12

Correct answer:

\displaystyle 3

Explanation:

Substitute three into the function of \displaystyle g(x)=3x to solve for \displaystyle g(3).

\displaystyle g(3)=3(3)=9

Substitute this value into the function \displaystyle f(x) = 3.

\displaystyle f(9)=3

There is no x-variable to substitute nine, which means the function is equal to three.

The answer is:  \displaystyle 3

Example Question #31 : Function Notation

If \displaystyle x=4 and \displaystyle y=6, determine:  \displaystyle 2(x+2y)  

Possible Answers:

\displaystyle 26

\displaystyle 36

\displaystyle 20

\displaystyle 24

\displaystyle 32

Correct answer:

\displaystyle 32

Explanation:

Substitute the assigned values into the expression.

\displaystyle 2(x+2y)=2(4+2(6))

Simplify the inside parentheses.

\displaystyle = 2(4+12) = 2(16) = 32

The answer is:  \displaystyle 32

Example Question #41 : Function Notation

What is the value of \displaystyle 3b^2-5c^3 if \displaystyle b=2 and \displaystyle c=-1?

Possible Answers:

\displaystyle 17

\displaystyle 15

\displaystyle 22

\displaystyle 12

\displaystyle 21

Correct answer:

\displaystyle 17

Explanation:

Substitute the assigned values into the expression.

\displaystyle 3b^2-5c^3 = 3(2)^2-5(-1)^3

Simplify by order of operations.

\displaystyle = 3(4)-5(-1) = 12+5 = 17

The answer is:  \displaystyle 17

Example Question #171 : Introduction To Functions

Determine the value of \displaystyle \frac{a}{c}-\frac{b}{d} if:  \displaystyle a=1, b=2,c=3, d=5.

Possible Answers:

\displaystyle -\frac{11}{15}

\displaystyle -\frac{1}{15}

\displaystyle -\frac{6}{5}

\displaystyle \frac{1}{15}

\displaystyle -\frac{11}{6}

Correct answer:

\displaystyle -\frac{1}{15}

Explanation:

Substitute the values of \displaystyle a=1, b=2,c=3, d=5 into the expression.

\displaystyle \frac{a}{c}-\frac{b}{d} = \frac{1}{3}-\frac{2}{5}

In order to subtract these fractions, we will need a least common denominator.

Multiply the denominators together for the LCD.  Convert the two fractions.

\displaystyle \frac{1}{3}-\frac{2}{5} = \frac{1(5)}{3(5)}-\frac{2(3)}{5(3)} = \frac{5}{15}-\frac{6}{15}

Subtract the numerators now that the denominators are common.

The answer is:  \displaystyle -\frac{1}{15}

Example Question #171 : Introduction To Functions

Determine the value of \displaystyle a^3-b^2-c if:  \displaystyle a=-1, b=-3, c=-5

Possible Answers:

\displaystyle 7

\displaystyle -5

\displaystyle 9

\displaystyle 13

\displaystyle 5

Correct answer:

\displaystyle -5

Explanation:

Given the expression \displaystyle a^3-b^2-c and the assigned values, substitute the values into the expression.

\displaystyle (-1)^3-(-3)^2-(-5)

Simplify this expression by order of operations.

\displaystyle -1-(9)+5 = -10+5 = -5

The answer is:   \displaystyle -5

Example Question #41 : Function Notation

Evaluate \displaystyle a^2-b^3 if \displaystyle a=-6 and \displaystyle b =-3

Possible Answers:

\displaystyle 3

\displaystyle 73

\displaystyle 21

\displaystyle 63

\displaystyle 9

Correct answer:

\displaystyle 63

Explanation:

Substitute the known values into the expression.

\displaystyle a^2-b^3 = (-6)^2-(-3)^3

Simplify the expression.

\displaystyle 36-(-27) = 36+27 = 63

The answer is:  \displaystyle 63

Example Question #41 : Function Notation

If \displaystyle a=-1 and \displaystyle b= -2, what is \displaystyle a^b\times b^a

Possible Answers:

\displaystyle -8

\displaystyle -\frac{1}{2}

\displaystyle -\frac{1}{4}

\displaystyle -2

\displaystyle 2

Correct answer:

\displaystyle -\frac{1}{2}

Explanation:

Substitute the assigned values into the expression.

\displaystyle (-1)^{(-2)}\times (-2)^{(-1)}

Simplify the negative exponents by rewriting both terms as fractions.

\displaystyle x^{-a} =\frac{1}{x^a}

\displaystyle (-1)^{(-2)}\times (-2)^{(-1)}= \frac{1}{(-1)^2} \times \frac{1}{(-2)^{1}}

Simplify the fractions.

\displaystyle 1\times \frac{1}{-2} = -\frac{1}{2}

The answer is:  \displaystyle -\frac{1}{2}

Example Question #173 : Functions And Graphs

If \displaystyle f(2)=5, what must \displaystyle A be?  \displaystyle y = 3x(A-7)

Possible Answers:

\displaystyle \frac{56}{3}

\displaystyle \frac{107}{15}

\displaystyle \frac{81}{4}

\displaystyle \frac{97}{6}

\displaystyle \frac{47}{6}

Correct answer:

\displaystyle \frac{47}{6}

Explanation:

Substitute the known value of \displaystyle x=2, y=5 into the equation.

\displaystyle 5= 3[2](A-7)

Simplify the equation.

\displaystyle 5=6(A-7)

Solve the right side by distribution.

\displaystyle 5=6A-42

Add 42 on both sides.

\displaystyle 5+42=6A-42+42

\displaystyle 47=6A

Divide by six on both sides.

\displaystyle \frac{47}{6}=\frac{6A}{6}

The answer is:  \displaystyle \frac{47}{6}

Example Question #47 : Function Notation

If \displaystyle f(2) = 4, what must \displaystyle k equal in \displaystyle f(x) = 5x-k?

Possible Answers:

\displaystyle 18

\displaystyle 6

\displaystyle -18

\displaystyle -14

\displaystyle -8

Correct answer:

\displaystyle 6

Explanation:

The term \displaystyle f(2) = 4 means that \displaystyle f(x)=4 when \displaystyle x=2.

Substitute the terms in the function to solve for \displaystyle k.

\displaystyle 4 = 5(2)-k

Solve for \displaystyle k.

\displaystyle 4 = 10-k

Subtract 10 on both sides.

\displaystyle 4 -10= 10-k-10

\displaystyle -6 =-k

Divide by negative one to eliminate the negative signs.

\displaystyle \frac{-6 }{-1}=\frac{-k}{-1}

The answer is:  \displaystyle 6

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