ExamBro
ExamBro
AP EAMCET · Maths · Application of Derivatives

If the tangent drawn to the curve \(y=x^3-a x^2+x+1\) at each point \(x \in \mathbb{R}\), is inclined at an acute angle with the positive direction of \(\mathrm{X}\) - axis, then the set of all possible values of ' \(a\) ' is

  1. A \(\mathbb{R}-(-\sqrt{3}, \sqrt{3})\)
  2. B \([-3,3]\)
  3. C \(\mathbb{R}\)
  4. D \((-\sqrt{3}, \sqrt{3})\)
Verified Solution

Answer & Solution

Correct Answer

(D) \((-\sqrt{3}, \sqrt{3})\)

Step-by-step Solution

Detailed explanation

Given \(y=x^3-a x^2+x+1\) \[ \Rightarrow \frac{d y}{d x}=3 x^2-2 a x+1 \] Since \(\theta\) is an acute angle. Hence \(\tan \theta>0\) \[ \Rightarrow 3 x^2-2 a x+1>0 \] Which is true off \(A>0\) and…