Fractions can be added and subtracted only if they're fractions

Find the value of the cosine for angle a

Given that ot =5, xt=12, and ox= 13 is xy tangent to circle o at t? explain.

If you flip a coin 3 times, what is the probability of flipping heads 3 times? a. p(3 heads) = 3/8 b. p(3 heads) = 1/6 c. p(3 heads) = 1/8 d. p(3 heads) = 1/2