∵f(x)=ax2+bx+c and g(x)=px2+qx Since, g(1)=f(1) ⇒p+q=a+b+c ......(i) and g(2)−f(2)=1 ⇒4p+2q−4a−2b−c=1 ........(ii) also g(3)−f(3)=4 ⇒9p+3q−9a−3b−c=4 .......(iii) From Eqs. (i) and (ii) 2p=2a−c+1 Now, g(4)−f(4) =16p+4q−16a−4b−c =12p+4(p+q)−16a−4b−c=6−3c