The curve passes through . The normal to the curve at this point meets the -axis at . What is ?

Answer and explanation

Correct answer: A. 18

  1. Step 1: Differentiate to find the tangent gradient: . At , .
  2. Step 2: The normal is perpendicular to the tangent, so its gradient is . Write the equation of the normal passing through : .
  3. Step 3: Set to find the -intercept : .
Answer
18.

Practise more Differentiation.

Free questions with an explanation for every one, and full timed Cambridge A-Level mock tests.

All Differentiation questionsTake a mock test

More Differentiation questions

Revise with flashcards

The curve y=x 2+8/x… | Cambridge A-Level Differentiation