00:01
So in this problem, we're being asked to verify the given identity that the tangent of the inverse sign of x is equal to x divided by the square root of 1 minus x squared.
00:09
And the best way to do this is geometrically.
00:12
So i'm going to focus on the left -hand side of this equation.
00:14
So inside our parentheses, we have the inverse sign of x.
00:17
Remember, when you find the inverse sign of something, that's always going to give you an angle measure.
00:22
So now, then what we need to do is find the tangent of that angle.
00:25
Well, let's go ahead and draw this triangle in the first quadrant.
00:28
So let's say that this is my angle, which i'm calling alpha.
00:32
Well, remember, the sign ratio is the opposite side over the hypotenuse.
00:36
So in this case, because it's the inverse sign of x, which would be like x over 1, the opposite side is x and iponetuce is 1...