For the curve , what is at the point ?

Answer and explanation

Correct answer: B.

  1. Step 1: Check the point: , so is on the curve.
  2. Step 2: Differentiate implicitly: , so .
  3. Step 3: At : .
Answer
.
Why not the others: inverts the fraction; loses the minus sign; comes from using in the numerator.

Practise more Algebra and Differential Calculus.

Free questions with an explanation for every one, and full timed Thanawiya Amma (Egypt) mock tests.