If f(x)= ∫(21,x) t^5 dt then f'(x).

Question

my answer was 1/6 (21^6-x^6) it said it's wrong.

Answer 1

You must be Mily from below.

same thing as before

∫ t^5 dt from t=21 to t=x
= (1/6)t^6 from t-21 to t=x
= (1/6)x^6 - (1/6)(21)^6
= (1/6)(x^6 - 21^6)

Answer 2

what about f ' (x)?
i did with (1/6)(x^6-21^6) but its wrong

f(x)=∫(21,x) t^5
f'(x)= x^5
i font know

Answer 3

but thanks

Answer 4

i got it, it correct answer is f'(x)=-x^5.