Mathematics · Functions

JEE Main 2026 — 24 January, Morning Shift — Question 6

If the domain of the function f(x)=log⁡(10x2−17x+7)(18x2−11x+1)f(x)=\log _{\left(10 x^{2}-17 x+7\right)}\left(18 x^{2}-11 x+1\right) is (−∞,a)∪(b,c)∪(d,∞)−{e}(-\infty, a) \cup(b, c) \cup(d, \infty)-\{e\}, then 90(a+b+c+d+e)90(\mathrm{a}+\mathrm{b}+\mathrm{c}+\mathrm{d}+\mathrm{e}) equals:

  1. Option A:

    170

  2. Option B:

    177

  3. Option C:

    307

  4. Option D:

    316

    Correct

Answer: D

Step-by-step solution

18x2−11x+1>018 x^{2}-11 x+1>0

(2x−1)(9x−1)>0(2 \mathrm{x}-1)(9 \mathrm{x}-1)>0

x<19\mathrm{x}<\frac{1}{9} or 12<x\frac{1}{2}<\mathrm{x}

Also 10x2−17x+7>010 \mathrm{x}^{2}-17 \mathrm{x}+7>0

(x−1)(10x−7)>0(\mathrm{x}-1)(10 \mathrm{x}-7)>0

x<710\mathrm{x}<\frac{7}{10} or 1<x1<\mathrm{x} &10x2−17x+7≠1 10 \mathrm{x}^{2}-17 \mathrm{x}+7 \neq 1

x∈(−∞,19)∪(12,710)∪(1,∞)−{65}x \in\left(-\infty, \frac{1}{9}\right) \cup\left(\frac{1}{2}, \frac{7}{10}\right) \cup(1, \infty)-\left\{\frac{6}{5}\right\}

90(a+b+c+d+e)=90(19+12+710+1+65)90(\mathrm{a}+\mathrm{b}+\mathrm{c}+\mathrm{d}+\mathrm{e})=90\left(\frac{1}{9}+\frac{1}{2}+\frac{7}{10}+1+\frac{6}{5}\right)

=10+45+63+90+108=316=10+45+63+90+108=316

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Mathematics
Chapter
Functions
Topic
Domain & range of functions
If the domain of the function f(x)=log (10 x 2 -17 x+7 ) (18 x 2 -11… | JEE Main 2026 PYQ with Solution · DhiX AI