I would like to solve the below: int arcsin(x)^1/2/(1-X)^1/2 But I don't know where and how to enter the function.

Your expression is ambiguous: There is a function named int( which extracts the integer part of a numerical result. But there is nothing enlightening about it: int(25/3) gives 8 as result
Do you mean to calculate the integral?
Is it arc sin of square root of X or square root of arcsin(X)?
I am going to assume you want to calculate the indefinite integral of [arcsin (square root of X)]/(1-X)^(1/2)

In Main calculator screen tap the Down pointing arrow at the left of the tool bar (left of the Edit Menu). Select Settings>SetUp>Basic Format



As you can see, the angle unit must be in Radians. Make sure that the Decimal calculation is unchecked, otherwise yoy will get a numerical result.
Press the keyboard key to enter your expression.

1. Press the 2D keyboard
2. Use the pen to tap the arrow close to the 0 to reveal the Integral template and tap it
3. Tap the arrow again to reveal the fraction template.
4. Tap it to insert it at the cursor position.
5. Tap mth to open the mathematics tab
6. At the bottom of the mth Tab press TRIG
7. Tap the arc sine key (sin^-1) and insert it in the numerator of the fraction.
8. Press the U-turn arrow at the bottom of the mth keyboard to exit the trigonometric functions.
9. Tap the square root function to the right of the natural log, tap the variable x and right parenthesis, on physical or soft keyboards.
10. Tap the down arrow to move cursor to the denominator of the integrand.
11. Type in the denominator (square root of (1-x))
12. Use the right arrow to move the cursor to main line, and one more tap to move cursor after the d, press the x key enter the differential.