# Trigonometry

Not what you're looking for? Search our solutions OR ask your own Custom question.

1)If sin(t) = -5/13 and 270 degrees is less than or

equal to t and is less than or equal to 360 degrees,

then cos(t)=?

2)If 0 degrees is less than t and less than 90 degrees

and cos(t) = 4/5, then cos(2t)=?

3)A right triangle is shown, sec(t) =? . |

1 = hypotenuse . |

x = y side of triangle . | x

t = inside angle < t___________|

https://brainmass.com/math/trigonometry/trigonometry-functions-angles-2481

#### Solution Preview

1) Using that cos^2+sin^2=1 we get: cos(t)^2=1-25/169=144/169=(12/13)^2 so cos(t)=12/13 or cos(t)=-12/13. Because t is in the fourth quarter, cos(t) ...

#### Solution Summary

This shows how to work with trigonometric functions and angles.

$2.49