What does "area" mean in a circle?​

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)

Which of the following values have 3 significant figures? check all that apply. a. 10.1 b. 100.05 c. 120 d. 129

The discrete random variables x and y take integer values with joint probability distribution given by f (x, y) = a(y−x+1) 0 ≤ x ≤ y ≤ 2 or =0 otherwise, where a is a constant. 1 tabulate the distribution and show that a = 0.1.2 find the marginal distributions of x and y. 3 calculate cov(x, y).4 state, giving a reason, whether x and y are independent. 5 calculate e(y|x = 1).