Original
How many antiderivatives does {{MATH_15}} have?
{{CMD_16}}
{{CMD_17}}
{{CMD_18}}none{{CMD_19}}
{{CMD_20}}one{{CMD_21}}
{{CMD_22}}infinitely many{{CMD_23}}
{{CMD_24}}
{{CMD_25}}
{{CMD_26}}
{{CMD_27}}
{{ENV_28}}
{{COMMENT_29}}
{{COMMENT_30}}
{{COMMENT_31}}
{{COMMENT_32}}
{{CMD_33}}
The functions {{MATH_34}}, {{MATH_35}}, {{MATH_36}}, {{MATH_37}} and so on, are all
antiderivatives of {{MATH_38}}.
It is clear that any function {{MATH_39}}, where {{MATH_40}} is a constant, is an antiderivative of {{MATH_41}}. Why?
Because, {{MATH_42}}.
Could there exist any other antiderivative of {{MATH_43}}, call it {{MATH_44}}, such that {{MATH_45}} is not a sum of {{MATH_46}} and a constant?
In that case, for all {{MATH_47}} we would have
{{MATH_48}}
{{CMD_49}}
Recall: Any function whose derivative is equal to {{MATH_50}} on some interval is equal to a constant on that interval. This means that
the function {{MATH_51}}, for some constant {{MATH_52}}. This implies that {{MATH_53}}, for all x.
{{CMD_54}}