Skip to content

CA Foundation · Quantitative Aptitude · Differential and Integral Calculus

If y = (3x + 2)/(x − 1), then dy/dx at x = 2 is:

Using the quotient rule, the derivative simplifies to −5/(x − 1)². At x = 2 the denominator equals 1, so dy/dx is −5.

  1. A−5Correct
  2. B5
  3. C−8
  4. D−1

Explanation

By the quotient rule, dy/dx = [3(x − 1) − (3x + 2)(1)]/(x − 1)² = −5/(x − 1)². At x = 2, (x − 1)² = 1, so dy/dx = −5. Reversing the numerator subtraction would give +5, which is wrong.

Did you get it right without looking?

One question tells you little. A timed set on Differential and Integral Calculus shows your real accuracy, how long you take and where you lose marks.

Practise Differential and Integral CalculusFree diagnostic mock

More Differential and Integral Calculus questions