For the function y=f(x), find f’(a)

-1/4

Step-by-step explanation:

f(x) = 1/(x+1)

f(a) = 1/(a+1)

f'(a) = {(a+1)×d/da (1) - d/da (a+1) × 1}/(a+1)²

f'(a) = {(a+1)×0 - 1×1}/(a+1)²

f'(a) = (0-1)/(a²+2a+1)

f'(a) = -1/(1+2a+a²)

putting a = 1

f'(a) = -1/(1+2+1)

f'(a) = -1/4

i dont know men

step-by-step explanation:

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81