So, using this unit circle and the line segment tangent to it... if an angle theta is in standard position so that the x -axis segment is labeled with a value of 1, and the Y-axis of the angle theta is equal to the tangent y/x... the hypotenuse is equal to the trig function secant, correct? and using the pythagorean theorum you would find a value for that hypotenuse by using 1 squared + y/x squared = c squared, correct? can you show me the work down to where this answer book gives 1/x is sec of theta? thanks