sir bansalquadratic eq page 24 q5 page 58 q 7 PROGRESSION PAGE #) THE2nd illustration seems wrong binomial page 45 q15

Pg 24 Q5
For 2^nd Equation a²⁽b²-c²)x² + b²(c²-a²)x + c²(a²-b²)=0
Clearly sum of coefficients is 0 i.e. 1 is the root

Since this has equal roots and one commot with 4x²sin² – 4xsin + 1
1 is root of this equation
4(1)²sin² -4(1)sin +1 =0
4 sin² – 4sin + 1=0
(2sin -1)²=0
or sin =1/2
Cleary = /6 or 5/6 satisfying the given condition.