Exponentials & Logs (DP IB Applications & Interpretation (AI): HL): Exam Questions

3 hours29 questions
1a
3 marks

Let l o g subscript 2 space 16 equals l o g subscript 2 a to the power of b comma where a and b are integers and a less than b.

(i) Find the values of a and b.

(ii) Hence, or otherwise, find the value of l o g subscript 2 space 16.

1b
2 marks

Let log space 25 plus log space 4 equals log space c.

(i) Find the value of c.

(ii) Hence, or otherwise, find the value of log space 25 plus log space 4.

1c
2 marks

Let l o g subscript 5 space 500 minus l o g subscript 5 space 4 equals l o g subscript 5 space d.

(i) Find the value of d.

(ii) Hence, or otherwise, find the value of l o g subscript 5 space 500 minus l o g subscript 5 space 4.

2a
2 marks

Let x equals ln space 15 and y equals ln space 3. Write down the following expressions in terms of x and y.

ln space 5.

2b
2 marks

ln space 45.

2c
3 marks

ln space 135.

3a
2 marks

Let r equals log space 2 and s equals log space 12. Write down the following expressions in terms of r and s.

log space 24.

3b
3 marks

log space 3.

3c
3 marks

log space 72.

4a
2 marks

Simplify the following:

fraction numerator open parentheses 4 x y to the power of negative 2 end exponent close parentheses open parentheses negative 12 x to the power of negative 4 end exponent y to the power of 12 close parentheses over denominator 6 x squared y end fraction.

4b
2 marks

open parentheses 2 x to the power of negative 1 end exponent y to the power of negative 2 end exponent close parentheses to the power of negative 3 end exponent open parentheses 4 x squared y cubed close parentheses to the power of 4.

4c
2 marks

square root of open parentheses 9 x to the power of 6 y to the power of negative 2 end exponent z to the power of 4 close parentheses end root cubed space open parentheses 3 x y z close parentheses to the power of negative 2 end exponent.

5
5 marks

Solve the equation 2 minus x square root of 3 equals fraction numerator 7 x over denominator square root of 3 end fraction comma giving your answer in the form fraction numerator square root of a over denominator b end fraction where a and b are integers.

State the values of a and b.

6a
2 marks

Given that l o g subscript a space 8 equals 3.

Find the value of l o g subscript a space 64.

6b
2 marks

Find the value of a.

6c
3 marks

Find the value of log subscript a squared end subscript space 8.

7a
2 marks

Let log subscript b space 3 equals x and space log subscript b 16 equals y

Find an expression for log subscript b space 9 in terms of x.

7b
2 marks

Find an expression for log subscript b space 4 in terms of y.

7c
3 marks

Find an expression for log subscript b space 48 in terms of x and y.

8a
2 marks

Show that fraction numerator open parentheses 4 minus 2 square root of x close parentheses over denominator 8 x end fraction squaredcan be written as 2 x to the power of negative 1 end exponent minus 2 x to the power of negative 1 half end exponent plus 1 half.

8b
2 marks

Given that 8 square root of 2 equals 2 to the power of a comma find the value of a.

8c
2 marks

Show that  fraction numerator x open parentheses 2 x to the power of 4 minus square root of x close parentheses over denominator x squared end fraction can be written as 2 x to the power of a minus x to the power of b comma where a and b rational numbers. State the value of a and b.

9
5 marks

Solve the equation 16 to the power of x minus 3 open parentheses 4 to the power of x plus 1 end exponent close parentheses equals 28. Write your answer in the form fraction numerator ln space a over denominator ln space b end fraction comma where a and b are integers.

10
5 marks

square root of 425 can be written in the form a square root of b. Find the values of a and b. Show all of your working.

11a
1 mark

The expression a to the power of 1 fifth end exponent cross times a to the power of 2 over 5 end exponent can be expressed in the form a to the power of p.

Find the value of p.

11b
2 marks

Let a to the power of 1 fifth end exponent cross times a to the power of 2 over 5 end exponent space equals 8.

Find the value of a.

11c
1 mark

The expression b cross times b to the power of negative 3 over 2 end exponent can be written in the form 1 over b to the power of q.

Find the value of q.

11d
2 marks

Let b cross times b to the power of negative 3 over 2 end exponent equals square root of 2

Find the value of b.

1a
2 marks

Let f left parenthesis x right parenthesis equals 5 space ln open parentheses x minus 7 close parentheses.

Find the values of x for which f open parentheses x close parentheses is undefined.

1b
3 marks

Given that point P has coordinates open parentheses p comma space 0 close parentheses, find the value of p.

2a
2 marks

Given that 2 to the power of m equals 8 and 2 to the power of n equals 16 comma write down the value of m and of n.

2b
4 marks

Hence or otherwise solve 8 to the power of 2 x plus 1 end exponent equals 16 to the power of 2 x minus 3 end exponent.

3a
3 marks

Write the expression 3 space ln space 2 minus ln space 4 in the form ln space k, where  k element of straight integer numbers.

3b
3 marks

Hence, or otherwise, solve 3 space ln space 2 minus ln space 4 equals negative ln space x.

4
5 marks

Solve the equation 49 to the power of p plus 4 end exponent equals 35 squared to the power of p for p. Express your answer in terms of ln space 7 and ln space 5.

5
5 marks

Solve the equation 4 to the power of x minus 3 cross times 2 to the power of x plus 2 end exponent equals 64.

6a
2 marks

Simplify the following expressions, giving your answers in the form a x to the power of n where a and n are rational numbers and any fractions are in lowest terms.

8 x to the power of negative 3 end exponent divided by 2 x to the power of negative 1 third end exponent

6b
2 marks

2 over 3 x to the power of 7 over 6 end exponent cross times 5 over 2 x to the power of negative 5 over 3 end exponent

6c
3 marks

open parentheses 3 x to the power of negative 2 over 3 end exponent close parentheses squared divided by 6 x to the power of negative 1 over 6 end exponent

7a
2 marks

Given that y equals 8 over 27 x to the power of 6 comma express each of the following in the form a x to the power of n comma where a and n are constants.

space y to the power of 1 third end exponent

7b
2 marks

y to the power of negative 1 end exponent

7c
3 marks

y to the power of negative 4 over 3 end exponent

8a
3 marks

A block of ice cream in the shape of a cuboid that has been taken out of the freezer and left at room temperature. The rate of decrease of the volume of the block of ice cream can be modelled by the formula

V equals A e to the power of x t end exponent

where A and x are constants and t is the time in minutes after the ice cream was removed from the freezer.

Before it was taken out of the freezer the block of ice cream measured 12 cm by 9 cm by 7 cm. Eight minutes later the block of ice cream measured 8.4 cm by 7.1 cm by 5.8 cm.

By taking logarithms of both sides, show that the rate of decrease of the volume of the block of ice cream can be rewritten as

x t space equals space ln space V space minus space ln space A

8b
4 marks

Find the value of x and A.

9a
5 marks

A zoologist is researching the connection between the mass of a particular breed of mouse, M g, and its heartrate, H bpm.  It is suggested that the relationship can be modelled by the equation

H equals k M to the power of x comma spacewhere x comma space k space element of straight real numbers.

The zoologist takes measurements from two different mice and records the data as follows.

Measurement

M open parentheses g close parentheses

H open parentheses b p m close parentheses

1

17.12

513

2

24.51

401

Find the values of x and k.

9b
3 marks

Use the model to predict

(i) the heartrate for a mouse of 20.2 grams,

(ii) the mass of a mouse that has a heartrate of 420 bpm.

1a
2 marks

Let f open parentheses x close parentheses equals ln space open parentheses x over 3 minus 1 close parentheses.

Find the values of x for which f open parentheses x close parentheses is undefined.

1b
2 marks

Given that point A has coordinates open parentheses a comma space 0 close parentheses, find the value of a.

2
6 marks

Solve 27 to the power of 4 x plus 2 end exponent equals 81 to the power of 8 x minus 3 end exponent.

3
6 marks

Solve 5 space ln space 2 space minus ln space 8 space equals negative ln space x.

4
6 marks

Solve the equation 216 to the power of k plus 2 end exponent equals 12 to the power of 3 k end exponent for k. Express your answer in terms of ln space 6 and ln space 2.

5
5 marks

Solve the equation 2 cross times 25 to the power of x minus 30 cross times 5 to the power of x minus 1 end exponent space equals space 1.

6a
3 marks

Simplify the following expressions, giving your answers in the form a x to the power of n where a and n are rational numbers and any fractions are in lowest terms.

open parentheses 8 x squared close parentheses to the power of negative 1 third end exponent cross times 1 fourth x to the power of negative 1 third end exponent

6b
3 marks

open parentheses 2 over 9 x to the power of 1 half end exponent cross times 1 over 18 x to the power of negative 3 over 4 end exponent close parentheses to the power of negative 1 fourth end exponent

6c
3 marks

open parentheses 8 x to the power of negative 2 over 3 end exponent close parentheses to the power of blank to the power of 2 over 3 end exponent end exponent over open parentheses 64 x to the power of negative 1 third end exponent close parentheses to the power of blank to the power of 1 third end exponent end exponent

7a
2 marks

Given that y equals 81 over 16 x to the power of negative 12 end exponent comma express each of the following in the form a x to the power of n comma where a and n are constants.

y to the power of 3 over 4 end exponent

7b
2 marks

y to the power of negative 1 half end exponent

7c
3 marks

open parentheses y to the power of 1 half end exponent close parentheses to the power of negative 3 end exponent

8a
4 marks

A company has conducted some product research and believes that their profit (P) made over time (t weeks after opening) can be modelled by the equation

P left parenthesis t right parenthesis equals R left parenthesis t right parenthesis minus C left parenthesis t right parenthesis comma

where

R open parentheses t close parentheses equals C open parentheses t close parentheses to the power of b over 100 t end exponent and C open parentheses t close parentheses equals a to the power of negative b t end exponent plus 1000

The company collects data on their revenue, R, and costs, C, at the end of each week. After exactly one week the company’s costs are $3000 and they make a loss of $1000.

Find the values of a and b.

8b
2 marks

Find the week in which the company first makes a positive profit.

8c
1 mark

Suggest a limitation to the company’s model.

9
6 marks

The rate, R, of increase of the volume of a cloud created in a science lab is related to the change in air temperature,T , and air pressure, P, by the equation

 R equals k T to the power of x P to the power of y, where x comma space y comma space k space element of space straight real numbers.

A meteorologist takes measurements at three intervals and records the data as follows.

Measurement

 bold italic R bold space stretchy left parenthesis c m cubed s to the power of negative 1 end exponent stretchy right parenthesis

 bold italic T bold space stretchy left parenthesis degree C stretchy right parenthesis

 bold italic P stretchy left parenthesis kPa stretchy right parenthesis

1

48.75

17.1

101.2

2

46.13

15.9

101.8

3

43.47

14.7

102.5

Find x comma space y spaceand k.