If equation x4−(3m+2)x2+m2=0 (m>0) has four real solutions which are in A.P., then the value of m is ________.

Let the roots be a - 3d, a - d, a + d, a + 3dSum of root=4a=0⇒a=0Hence, roots are -3d, -d, d, 3d.Product of roots =9d4=m2 ⇒ d2=m3            …… (1)Again Σx1x2=3d2−3d2−9d2−d2−3d2+3d2                    =−10d2=−(3m+2)or 10m3=3m+2 or 10m=9m+6or m = 6