The value of the expression
is 4 and the exact value of
is 
<h3>How to determine the trigonometry expression?</h3>
The point on the unit circle is given as:

A point on a unit circle is represented as: (x,y), such that:
cos(t) = x and sin(t) = y.
This means that:


Calculate tan(t) using:

So, we have:

Evaluate

The expression is then calculated as:

Evaluate each term

Evaluate the sum

Hence, the value of the expression
is 4
<h3>How to solve the arcsin expression?</h3>
The expression is given as:

As a general rule, the arc sine of sine x is x.
This means that:

Hence, the exact value of
is 
Read more about trigonometry expressions at:
brainly.com/question/8120556
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