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Exponents Powers and Roots — Free MYP4 Mathematics (Standard) Practice Questions
1QuestionLaws of Exponents for Integer PowersConcept Practice
2 marks~3 minCriterion B
Explain why am⋅an=am+n holds true, using repeated multiplication in your reasoning. [1]
Support your explanation with the example 23⋅22, showing each repeated-multiplication step clearly. [1]
Solutions
2QuestionSquare Roots and Cube RootsAssessment Practice
2 marks~3 minCriterion D
A square concrete slab has an area of 150m2. A foundation measures 12.2m wide.
a
Calculate the side length of the slab, giving your answer to one decimal place. [1]
b
The construction manager states: "An estimate is good enough — we don't need the exact value." Using your result from part (a), advise the manager whether a one-decimal-place estimate is sufficient to decide if the slab fits the foundation. [1]
Solutions
3QuestionLaws of Exponents for Integer PowersAssessment Practice
4 marks~6 minCriterion C
A biologist models two bacterial populations. Population A grows according to y=2x, where y is the population size (thousands) and x is time in hours. Population B decays and is modelled by y=2x1.
a
Show that 2x1=2−x, stating the law of exponents used. [1]
b
Describe the geometric transformation that maps the graph of y=2x onto the graph of y=2−x, explaining how the change in exponent produces this transformation. [2]
c
At x=3 hours, Population A has reached 8 thousand. Calculate the size of Population B at the same time, then justify whether this value is a realistic prediction for a decaying bacterial culture. [1]
Solutions
4QuestionSimplifying Expressions with ExponentsAssessment Practice
6 marks~9 minCriterion A
A materials scientist models the thermal conductivity of a composite alloy using the expression
(81c−8d1216a−4b6)−43
where a, b, c, d represent measurable physical parameters, all positive and non-zero.
a
Show that the expression simplifies to 8b29c627a3d9, stating each law of exponents you apply. [4]
b
The scientist states: "Because the outer exponent is negative, the simplified expression must always be less than 1." Critique this claim, justifying your reasoning with a specific numerical counterexample. [2]