Could you please help me solve this?

\fFor the function f: [a, b] x 10, 0o ) - IR holds: i) For all t E ( 0, co ) the function ft: [a, b] - RR, x + f (x, t) is differentiable . We define the partial derivative with respect to X : 2 x f ( x , t ) : = fx ( x ) . ii ) For all xE La, b] exists (f (x, t ) at and faxf ( x, t ) olt. in ) ( 2 x f (x, t ) at converges uniformly with respect to X E [ a , b]. ( 2 ) # E , > 0 3 R , > 0 V O 0 7 6 , 2 0 V X , , x 2 E [ a , b ] V t E [ R R ] : 1x ,- X21