If `a=(1)/(2),b=3` and `c=1` then find the value of `b^(2)-4ac`

If a=1, b=8, c=15, find the value of b^(2)-4ac .

If a= 3, b = 2 and c = 5 then find the value of a^2-3b^2+ac

If a=1,b=8,c=15, find the value of b^2-4ac.

If a=2,b= -11 , c = 15 , find the value of b^(2)- 4ac .

If a:b=3:1 and b:c=5:1 , then find the value of ((a^3)/(15b^2c))^3

If a+b+c=1 , ab+bc+ca=-2 and abc=1 then find the value of a^4+b^4+c^4

If a,b , c are in AP, then, find the value of (a-c)^2/(b^2-ac)

If tan A=(a)/(a+1) and tan B=(1)/(2a+1) then find the value of A+B=................. A) 0 B) pi/2 C) pi/3 D) pi/4