If cos(x)cos(π/7)+sin(x)sin(π/7)= - (√2)/2, then x can equal:
(check all that apply)
a. (π/4)+(π/7)+2nπ

b. (5π/4)+(π/7)+2nπ

c. (7π/4)+(π/7)+2nπ

d. (3π/4)+(π/7)+2nπ

The vertices of a rectangle are given in the columns of the matrix . if is found to perform a transformation, what are the coordinates of the transformed rectangle? (0, 0), (0, –3), (–3, –3), (–3, 0) (0, 0), (0, 3), (3, 3), (3, 0) (0, 0), (0, 3), (–3, –3), (–3, 0) (0, 0), (0, 3), (–3, 3), (–3, 0)

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60

This figure consists of a rectangle and semicircle. what is the perimeter of this figure use 3.14 for pi 60.84m 72.84m 79.68m 98.52m