We'll use the following properties of sine and cosine to prove this:



Then it's just a matter of filling it in...
sin20sin40 * sin60sin80 = 1/2(cos20 - cos60) * 1/2 (cos20 - cos140) =
1/8( cos40 + 1 - cos160 - cos120 - cos40 - cos80 + cos80 + cos200) =
1/8(1 - cos160 - cos120 + cos200) =
1/8(1 - cos160 - cos120 + cos160) =
1/8(1 - cos120 ) = 1/8( 1 + 1/2 ) = 3/16
Answer:
No solutions; parallel
Step-by-step explanation:
The equations x=16 and x=3 both have a slope of 0. So when graphed, they would be parallel and there are no solutions between parallel lines.
You have to use the quadratic formula to solve this. The zeros of this quadratic are 2 + sqrt2/2 and 2 - sqrt2/2, which in "real" numbers is 1.707 and .2928
X^2+2x-5x-10
x(x+2)-5(x+2)
(x-5)(x+2)
Hey there!
To start, the mean of the answer is also known as the average value of a set of numbers. This is calculated by dividing the sum of the set by the total amount of numbers.
In this case the sum of all the numbers is 13 + 6 + 8 + 6 + 15 which is equal to 48.
Now, divide 48 by the total number of numbers in the set: 48/5 = 9.6
Your final answer should be 9.6, or you can leave it in fraction form as 48/5.
Hope this helps!