Question

( a, b, c ) are in ( cos A, p )
( Rightarrow quad 10=frac{a+c}{2} )
( mathrm{Now} )
[
begin{aligned}
frac{(a-c)^{2}}{b^{2}-a c} &=frac{(a-c)^{2}}{left.left(frac{a+c}{2}right)^{2} cdot a cright)^{2}}
&=frac{4(a-c)^{2}}{a^{2}+c^{2}-2 a c}
&=frac{4(a-c)^{2}}{(a-c)^{2}}=4
end{aligned}
]

# la-c) 3. Ifa, b, c are in A.P, then is equal to (6- (A) 1 (B) 2 (C) 3 (D) 4 .

Solution