some easy calculus 1 questions

(1 point) Differentiate y = v arctan(x). =\f(1 point) If f (x) = (sin- (6x + 8)) , then f' (x) = Note: The inverse of sin(x) can be entered as arcsin(x) or asin(x)(1 point) Given that f (x) = 2x + cos(x) is onetoone, use the formula 1 -1, _ (f )(x) f'(f\"(x)) to find (1"1 )'(l). (f_1 W1) =