Sine, Cosine and Tangent Functions

Topic Page

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))# ?