Answer:
0.128rad/sec
Step-by-step explanation:
Let x represent the between the man and the point on the path
θ = the angle
dx/dt = 4 ft/s
dθ/dt = rate is the searchlight rotating when the man is 15 ft from the point on the path closest to the searchlight
tan θ = x/20 ft
Cross Multiply
20tan θ = x
dx/dt = 20sec² θ dθ/dt
dθ/dt = 1/20 × cos² θ dx/dt
dθ/dt= 1/20 × cos² θ × 4
dθ/dt = 1/5 × cos² θ
Note : cos θ = 4/5
dθ/dt = 1/5 × (4/5)²
dθ/dt = 16/125
dθ/dt = 0.128rad/sec
Answer: The answer is (D) 
Step-by-step explanation: Given that there is a rectangle, where length of the rectangle is given by

and width of the rectangle is given by

We are to find the perimeter of the rectangle. To do so, we need to add two times length with two times breadth of the rectangle.
Therefore, perimeter is given by

Thus, the correct option is (D).
Answer:
12 in the first option bro
By using the information you have, you can use make a proportion to solve this.
You burn 4 logs in 2 hours or 4/2. You are comparing this to your unknown number, x, over 8 hours. So it looks like this 4/2 = x/8. You read it as four logs in two hours is x logs in eight hours. To solve you cross multiply. You do 2 times x and 4 times eight. That would be 2x= 32. Your goal is getting x alone, so divide each side by 2. Your answer is x= 16 logs in eight hours. You can solve this different and maybe easier ways but this is the best way if you want to get used to going this in algebra. Hope that helps! :)