Let  x3+ax+1=0, x4+ax2+1=0  have a common root. Then a=

The given equations are x3+ax+1=0, x4+ax2+1=0 The equations have a common root. Then (x4+ax2+x)−(x4+ax2+1)=0 ⇒ x=1 is the common rootThen x3+ax+1=0  will be⇒ 1+a+1=0⇒a=−2