Let f (x) be continuous on the interval [a, b], then the value of ∫ f (x) DX - ∫ f (T) DT (the interval is [a, b]) is?
Because ∫ f (x) DX = ∫ f (T) DT (integral value is independent of variable)
So ∫ f (x) DX - ∫ f (T) DT = 0
Because ∫ f (x) DX = ∫ f (T) DT (integral value is independent of variable)
So ∫ f (x) DX - ∫ f (T) DT = 0