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.
Sketch the graph of L(d)L(d)L(d) for all d≠0d \neq 0d=0, clearly indicating the equations of any asymptotes.
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.
566 exam-style questions on OCR A Level Maths 1.2 Algebra and Functions, covering 1.2.1 Indices, 1.2.2 Surds, 1.2.3 Simultaneous equations, 1.2.4 Quadratic functions, 1.2.5 Completing the square, 1.2.6 Solving quadratic equations, 1.2.7 Inequalities, 1.2.8 Expressing solutions of inequalities, 1.2.9 Representing inequalities graphically, 1.2.10 Manipulating polynomials, 1.2.11 Simplifying rational expressions, 1.2.12 The modulus function (A-level only), 1.2.13 Graphs of functions, 1.2.14 Sketching curves from equations, 1.2.15 Sketching reciprocal curves, 1.2.16 Interpreting solutions graphically, 1.2.17 Intersection points of graphs, 1.2.18 Proportional relationships, 1.2.19 Graph of the modulus of a linear function (A-level only), 1.2.20 Solving modulus equations graphically (A-level only), 1.2.21 Definition of a function (A-level only), 1.2.22 Inverse and composite functions (A-level only), 1.2.23 Simple graph transformations, 1.2.24 Combinations of graph transformations (A-level only), 1.2.25 Partial fractions (A-level only), and 1.2.26 Models in context. Each one has a worked solution and a mark scheme showing where the marks go.