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Functions and Graphs

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Question 74

The intensity of radiation L  L \,L at a distance d  d \,d from a specific energy source is modeled by the function L(d)=1d4\displaystyle L(d) = \frac{1}{d^4}L(d)=d41​ for d>0d > 0d>0.

a.

Sketch the graph of L(d)L(d)L(d) for all d≠0d \neq 0d=0, clearly indicating the equations of any asymptotes.

[2]
b.

A revised model for a shielded source is given by M(d)=1256d4\displaystyle M(d) = \frac{1}{256d^4}M(d)=256d41​. The graph of L(d)L(d)L(d) can be transformed into the graph of M(d)M(d)M(d) using a single stretch parallel to one of the coordinate axes.

Student A claims that the required transformation is a stretch parallel to the LLL-axis. Student B claims that the required transformation is a stretch parallel to the ddd-axis.

Determine, providing mathematical justification, whether Student A is correct, Student B is correct, both are correct, or neither is correct.

[6]

Functions and Graphs Questions

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