SL 2.3—Graphing functions

Syllabus
First assessment 2021
Objective
Level
SL

Sketch a graph from structure and context

Sketch a graph from structure and context.

Use intercepts, turning points, asymptotes, scale and context to sketch the shape before relying on a calculator.

Worked example
A revenue graph crossing the x-axis at 0 and 100 has break-even intercepts; label what each axis means.

Worked example
What makes a sketch usable? labelled axes and key features, not artistic smoothness.

Common boundary
A calculator trace without scale or labels is not a mathematical interpretation.

Sums and differences are graphed pointwise: if f(x)=x2f(x)=x^2 and g(x)=2xg(x)=2x, then (f+g)(x)=x2+2x(f+g)(x)=x^2+2x and (fg)(x)=x22x(f-g)(x)=x^2-2x. Generate or sketch each new function, then label axes, intercepts, extrema and any context-specific units. Do not add the visual heights without first checking both functions share the same input domain.