I have 3 problems I'm struggling with. Any help would be great

1) Given the function below

f(x)=100x3+253

-Find the equation of the tangent line to the graph of the function at x=1. Answer in mx+b form.

(Now, I found the derivative (100x^2)/(100x^3+25)^2/3. I then plugged 1 in as x and got 4, and when putting it into the point-slope form equation, I get 4x. But for some reason, the test I'm taking is telling me this is wrong, so I'm stumped already.)

The rest goes..

-Use the tangent line to approximate f(1.1).

-Compute the actual value of f(1.1). What is the error between the function value and the linear approximation?

Answer as apositive value only.Approximate to 5 decimal places.

2. Let's explore the function below using the Mean Value Theorem.

f(x)=(7x-21)3There are two x-values where the slope of the tangent line to the graph equals the slope of the secant line between x=0 and x=9. To find them, follow the steps below.

[A] First, find the slope of the secant line between x=0 and x=9.

(With this one, I already know the answer is 9261).

[B] Now, find the derivative of the function.

(I already know this one is 21(7x-21)^2)

C] Set the derivative equal to mSEC and solve. One of these values is x=0, what is the other?

(But with this one, I have no idea where x=0 comes from, and when I set it equal to the slope if get 23/7, which ends up not being correct).

3. box with a square base andopen topmust have a volume of 70304 cm3. We wish to find the dimensions of the box that minimize the amount of material used.

First, find a formula for the surface area of the box in terms of only x, the length of one side of the square base.

[Hint: use the volume formula to express the height of the box in terms of x.]

Simplify your formula as much as possible.

(With this one, I need A(x), A'(x), A"(x), and the evaluation of A"(x) at the x value where A'(x) = 0)

Pleeeasse help. If you can help with any, I would be in your debt for sure!