PLEASE HELP ASAP WILL GIVE BRAINLIEST AND 100 POINTS TO EACH ANSWERER! A biologist is studying the growth of a particular species of algae. She writes the following equation to show the radius of the algae, f(d), in mm, after d days:

f(d) = 7(1.06)d

Part A: When the biologist concluded her study, the radius of the algae was approximately 13.29 mm. What is a reasonable domain to plot the growth function? (4 points)

Part B: What does the y-intercept of the graph of the function f(d) represent? (2 points)

Part C: What is the average rate of change of the function f(d) from d = 4 to d = 11, and what does it represent? (4 points)

fd=(7)(1.06)d

Step 1: Add -7.42d to both sides.

df+−7.42d=7.42d+−7.42d

df−7.42d=0

Step 2: Factor out variable d.

d(f−7.42)=0

Step 3: Divide both sides by f-7.42.

d(f−7.42)f−7.42=0f−7.42

d=0f−7.42

d=0f−7.42

Step-by-step explanation:

fd=(7)(1.06)d

Step 1: Add -7.42d to both sides.

df+−7.42d=7.42d+−7.42d

df−7.42d=0

Step 2: Factor out variable d.

d(f−7.42)=0

Step 3: Divide both sides by f-7.42.

d(f−7.42)f−7.42=0f−7.42

d=0f−7.42

d=0f−7.42

Step-by-step explanation:

Step-by-step explanation:

step-by-step explanation:

infinity is the answer

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