Answer: 30.48
Step-by-step explanation:
Sum the series of 30.48 + (1/2)(30.48)+ (1/4)(30.48)+(1/8)(30.48)+(1/16)(30.48)+(1/32)(30.48)
Or use an Excel spreadsheet
Find answer showing detailed workings in the image
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:
46
Step-by-step explanation:
Let
represent a number with
in the ten's position and
is the one's position.
This means
actually has value of
.
We are given the sum of those digits of
is 10; this means
.
It says if 18 is added to the number
, then the result is
.
So
has value
and
has value
.
We are given then:


Subtract
on both sides:

Simplify:

Subtract
on both sides:


Divide both sides by 9:

Rearrange by commutative property:

So the system of equations we want to solve is:


-------------------------Add equations together (this will eliminate the variable
and allow you to go ahead and solve for
:


Divide both sides by 2:

Simplify:

If
and
, then
.
since 4+6=10.
So the original number is (46).
18 more than 46 is 18+46=(64) which is what we wanted.
We also have the sum of 4 and 6 is 10 as well.
Answer:
y = -
x + 3
Step-by-step explanation:
Assuming you require the equation of the line
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Here m = -
, thus
y = -
x + c ← is the partial equation
To find c substitute (- 4, 6) into the partial equation
6 = 3 + c ⇒ c = 6 - 3 = 3
y = -
x + 3 ← equation of line