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