Mathematics · Functions

JEE Main 2026 — 22 January, Morning Shift — Question 5

Let f(x)=x2025−x2000,x∈[0,1]f(x)=x^{2025}-x^{2000}, x \in[0,1] and the minimum value of the function f(x)f(x) in the interval [0,1][0,1] be (80)80(n)−81(80)^{80}(\mathrm{n})^{-81}. Then n is equal to :

  1. Option A:

    -81

    Correct
  2. Option B:

    -40

  3. Option C:

    -41

  4. Option D:

    -80

Answer: A

Step-by-step solution

f(x)=x2025−x2000\mathrm{f}(\mathrm{x})=\mathrm{x}^{2025}-\mathrm{x}^{2000}

f′(x)=0⇒x=(20002025)1/25=α(\mathrm{f}^{\prime}(\mathrm{x})=0 \Rightarrow \mathrm{x}=\left(\frac{2000}{2025}\right)^{1 / 25}=\alpha( say ))

∴f(0)=0,f(1)=0,f(α)=(8081)80⋅−181=8080⋅(−81)−81\therefore f(0)=0, f(1)=0, f(\alpha)=\left(\frac{80}{81}\right)^{80} \cdot \frac{-1}{81}=80^{80} \cdot(-81)^{-81}

n=−81n=-81

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Mathematics
Chapter
Functions
Topic
Domain & range of functions
Let f(x)=x 2025 -x 2000 , x in[0,1] and the minimum value of the… | JEE Main 2026 PYQ with Solution · DhiX AI