Name: scott
Who is asking: Student
Level of the question: Secondary

Question: How to prove arc sin x = arc tan( (x)/√(1-x2))


Hi Scott,

Arc sin(x) is the angle whose sine is x. Hence if arc sin(x) = t then sin(t) = x. Think of the number x as x/1 then

sin(t) = x/1

Draw a diagram to represent this.  

Use Pythagoras theorem to find the length of the third side of the triangle.

What's the tangent of t?