If Rolle’s theorem holds for the function fx=x3−ax2+bx−4,x∈1,2 with  f'43=0 , then ordered paira,b  is equal to:

Since the function f(x) follows Rolles theorem, f1=f21−a+b+1=8−4a+2b+1⇒3a−b=7                  ......1differentiate the function with respect to xf'x=3x2−2ax+bf'43=03×169-2a×43+b=0163-8a3+b=0-8a+3b+16=08a-3b=16  ………(2)Solving the above two equations, we get a=5,b=8