The dreaded Cassio fx 115MS S-V.P.A.M.

Look at the color of the ALPHA key, and find if there is a second = of the same color as the ALPHA key. If there is one, you enter it as part of a mathematical equality by pressing [ALPHA] followed by the key with the second = sign marking. However, I do not see the purpose since the calculator does no accept algebraic expression. To enter a function for a table, you select the computational mode as TABLE and the calculator will display f(x)= .

Here it is

The syntax of the command is

where function is the expression you are differentiating
x is the value of variable x at which you are evaluating the derivative, and tol is the tolerance (the error) you are willing to tolerate in the result.

If you do not want to specify a tolerance just omit the last comma and tol.

To enter the command d/dx you use key sequence [SHIFT][Integral]
To enter the symbol x in the expression you press [ALPHA][ ) ]
To enter a comma you use [SHIFT] [ ) ]
To enter a power of 10 in the tolerance use [x10^X] key

Example : Calculate

The key sequence is as follows
[SHIFT] [Integral] 3 [ALPHA] [ ) ] [X^2] [-] 5 [ALPHA] [ ) ] +2 [SHIFT] [ ) ] 2 [SHIFT] [ ) ] 1 [x10^X] [(-)] 12 ) [=]

DO NOT confuse [SHIFT] [ ) ] which enters the comma and [ALPHA] [ ) ] which enters the variable X.

Press SHIFT MODE 1 to put the calculator into MathIO mode.

I am not sure what you mean, because your question already shows what you have to do.
To use the functions marked on the body of the calculator you use either the SHIFT key for the ALPHA key.
If a key has next to it (on the body of the calculator) two markings, the one on the left is accessed with SHIFT, and the one on the right with ALPHA. Colors of commands on calculator body are coordinated with the colors of the Shift key and the ALPHA key.

The question I am asking is whether you know what [SHIFT][COS] means. You probably do, but just in case you do not (no reflexion on your abilities)
[SHIFT] [COS] gives access to the arc cosine function, [SHIFT][SIN] the arc sine function, and [SHIFT][TAN] the arctangent.

1. I checked your problems. There are three questions asked by you. The first one concerns how to insert the = sign to create an algebraic equation. It was answered correctly by someone.
2. The second one also concerning the = is still awaiting a solution. But it was filed under Copiers.
3. The third question (this very one) is no question at all since you claim the site is sending you in circles.
   

Here is the solution to your two questions.
To insert an equal sign in an equation on the Casio FX-115ES one uses the key combination [ALPHA][CALC] (=).

To insert other variables (A,B,C,D,X,Y) you do as follows

[ALPHA][(-)] (A).
[ALPHA][' " "] (B).
[ALPHA][hyp] (C).
[ALPHA][sin] (D).
[ALPHA][ ) ] (X).
[ALPHA][S<=>D] (Y).

The only other uses of the [ALPHA] key are
[ALPHA][Integral] (:)
[ALPHA][M+] (M) to access constant memory register
[ALPHA][x10^x] (e) to access value of the base of the natural logarithm.

I checked your problems.

1. There are three questions asked by you. The first one concerns how to insert the = sign to create an algebraic equation. It was answered correctly by someone.
2. The second one also concerning the = is still awaiting a solution. But it was filed under Copiers.
3. The third question (this very one) is no question at all since you claim the site is sending you in circles.
   

Here is the solution to your two questions.
To insert an equal sign in an equation on the Casio FX-115ES one uses the key combination [ALPHA][CALC] (=).

To insert other variables (A,B,C,D,X,Y) you do as follows

[ALPHA][(-)] (A).
[ALPHA][' " "] (B).
[ALPHA][hyp] (C).
[ALPHA][sin] (D).
[ALPHA][ ) ] (X).
[ALPHA][S<=>D] (Y).

The only other uses of the [ALPHA] key are
[ALPHA][Integral] (:)
[ALPHA][M+] (M) to access constant memory register
[ALPHA][x10^x] (e) to access value of the base of the natural logarithm.

To input an = sign use: alpha, calc

Xy button

10 Xy 7 = 10,000,000