If cos a = 3/8 , then what is the positive value of cos 1/2 a, in simplest radical form with a rational denominator? guys plz me !

Somone me i want to know what 18 hours out of 24 hours in a fraction

Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.

An observer(o) spots a plane(p) taking off from a local airport and flying at a 29 degree angle horizontal to her line of sight and located directly above a tower(t). the observer also notices a bird circling directly above her. if the distance from the plane(p) to the tower(t) is 6,000ft., how far is the bird(b) from the plane(p).