Answer:
B 1/4
Explanation:
f(x) = y = x⁴ + 5
the inverse function is
y - 5 = x⁴
x = 4th root(y - 5)
now we rename y and x to make it a regular function definition :
g(x) = y = ±4th root(x - 5) = ±(x - 5)^(1/4)
because g(6) = 1 (positive), we have
g(x) = (x - 5)^(1/4)
and since we are using the positive branch, it means also that all the tangent slopes (= g'(x)) are positive.
g'(x) = 1/4 × (x - 5)^(-3/4) × 1 = 1/4 × (x - 5)^(-3/4)
because (x - 5)' = 1
g'(6) = 1/4 × (6 - 5)^(-3/4) = 1/4 × (1/1³)^(1/4) =
= 1/4 × 1^(1/4) = 1/4 × 1 = 1/4
please note, we are using only the positive root result in this case to get a positive result as tangent slope for g(x) as enforced by g(6) = 1.