Topic explanation

Standard explanation

At x=a, derivative gives tangent slope; normal slope is -1m when m is nonzero.

Key points

• Tangent, normal, and rate of change
• rule
• worked example
• Tangent, normal, and rate of change: At x=a, derivative gives tangent slope; normal slope is -1m when m is nonzero.
• CONCEPT AND RULE: At x=a, derivative gives tangent slope; normal slope is -1m when m is nonzero.
• METHOD: For tangent, normal, and rate of change, identify the given information and required result. Select
• At x=a, derivative gives tangent slope; normal slope is -1m when m is nonzero.
• Worked pattern: For y=x^2 at x=2, tangent slope is 4 and tangent is y-4=4(x-2).

Labelled diagram