Verified Solution • 2025–26 Session moderate

QJEEM22Ma0a52: JEE Main 2022 Mathematics - Class 12 JEEM22Ma0a52 Solution

The value of lim⁡x→1(x2−1)sin⁡2(πx)x4−2x3+2x−1\mathop {\lim }\limits_{x \to 1} {{({x^2} - 1){{\sin }^2}(\pi x)} \over {{x^4} - 2{x^3} + 2x - 1}} is equal to:

Multiple Choice Options

  • A π26{{{\pi ^2}} \over 6}
  • B π23{{{\pi ^2}} \over 3}
  • C π22{{{\pi ^2}} \over 2}
  • D π\pi 2

Step-by-Step Verified Solution

lim⁡x→1(x2−1)sin⁡2(πx)x4−2x2+2x−1\mathop {\lim }\limits_{x \to 1} {{({x^2} - 1){{\sin }^2}(\pi x)} \over {{x^4} - 2{x^2} + 2x - 1}}

=lim⁡x→1(x2−1)sin2(πx)(x2−1)(x−1)2= \mathop {\lim }\limits_{x \to 1} {{({x^2} - 1)si{n^2}(\pi x)} \over {({x^2} - 1){{(x - 1)}^2}}}

=lim⁡x→1sin⁡2(πx)(x−1)2= \mathop {\lim }\limits_{x \to 1} {{{{\sin }^2}(\pi x)} \over {{{(x - 1)}^2}}}

Let x=1+hx = 1 + h

∴\therefore when x →\to 1 then h →\to 0

=lim⁡h→0sin⁡2(π(1+h))(1+h−1)2= \mathop {\lim }\limits_{h \to 0} {{{{\sin }^2}(\pi (1 + h))} \over {{{(1 + h - 1)}^2}}}

=lim⁡h→0sin⁡2(πh)h2= \mathop {\lim }\limits_{h \to 0} {{{{\sin }^2}(\pi h)} \over {{h^2}}}

=lim⁡h→0π2×sin⁡2(πh)(πh)2= \mathop {\lim }\limits_{h \to 0} {\pi ^2} \times {{{{\sin }^2}(\pi h)} \over {{{(\pi h)}^2}}}

=π2×1= {\pi ^2} \times 1

=π2= {\pi ^2}

Related Learning Resources & Exam Preparation