To solve this, it might be easier to draw it out (see the picture below). I split it into two triangles and used trig functions to find the altitude. I used the big triangle to find theta, and the used theta to find the side of the altitude. *remember that sine= opposite/hypotenuse*
Answer:
<h2>4 p.m.</h2>
Step-by-step explanation:
We know that a day contains 24 hours in total.
The time already passed will be represented by 
.
The remaining time would be 
, becasye half of what has already passed remains until the end of the day.
Basically, the sum of these two expression gives 24 hours in total.
Therefore, the actual time is 4 p.m.
Answer:
Ok, first in our series we can see two numbers in the Sigma, one bellow 0, and other above, 4.
This means that the value of k will go from 0 to 4, then all the numbers in the sum are:
(-1/2)^0 + (-1/2)^1 + (-1/2)^2 + (-1/2)^3 + (-1/2)^4
So we have 5 terms in our series.
b) to see the sign in each term, we must solve the powers, remember that:
(-1)^n is -1 if n is odd, and is equal to 1 if n is even, so we have:
(-1/2)^0 + (-1/2)^1 + (-1/2)^2 + (-1/2)^3 + (-1/2)^4
= 1 -1/2 + 1/4 - 1/8 + 1/16.
So the sign in each term of the series alternates.
But you're already done....
