Three distinct numbers a,b,c, a E N forms GP and b,a,c, form an AP then minimum value of c^2 +4b+1 is-

1 0

2 9

3 4

4 1

Hii
Use the concept of middle term of AP n Middle term of GP. From there you will get a quadratic equation in “b” and “c”. After finding out roots of the quadratic equation you will see that the only possible value of “b” is “c”. Hence the given question will get converted to b^2 +4b+1 whose minimum value is 1.