Sine, Cosine and Tangent Functions Geometry Right Triangles and Trig Sine, Cosine and Tangent Functions 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 descend if the airport is 50 miles away? Question #02b52 How to simplify sin(sec^(-1)(x)) ? How to simplify tan(sec^(-1)(x)) ? How do you simplify sec(tan^(-1)(x)) ? Right Triangles and Trig View all chapters Pythagorean Theorem Pythagorean Theorem Proofs Special Right Triangles Sine, Cosine and Tangent Functions Trig Ratios and Similarity Prev Next