How to simplify sin(sec^(-1)(x)) ? Geometry Right Triangles and Trig Sine, Cosine and Tangent Functions 1 Answer Guillaume L. Aug 2, 2018 sin(sec^(-1)(x))=sqrt(x^2-1)/x Explanation: sin(sec^(-1)(x))=sin(cos^(-1)(1/x)) Let y=cos^(-1)(1/x) x=1/cos(y) 1/x^2=cos(y)^2=1-sin(y)^2 1/x^2-1=-sin(y)^2 (x^2-1)/x^2=sin(y)^2 sqrt(x^2-1)/x=sin(y)=sin(sec^(-1)(x)) \0/ here's our answer ! Answer link Related questions Why is the cosine of an obtuse angle negative? How would I solve cos x + cos 2x = 0? Please show steps. If A is an acute angle and sin A = .8406, what is angle A round to the nearest tenth of a degree? Question #a69e0 If sin B = -12/13 then what is cos 2B ? An airplane is at height of 10000 feet. At what angle (rounded to whole degree), it must... Question #02b52 How to simplify tan(sec^(-1)(x)) ? How do you simplify sec(tan^(-1)(x)) ? See all questions in Sine, Cosine and Tangent Functions Impact of this question 35255 views around the world You can reuse this answer Creative Commons License