Assuming angle a and angle b are not equal and the given triangle is a right triangle .
Let's see cos(90-b)
Here we use the formula of cos(A-B)=cos A cos B -sin A sin B
And on using this formula,we will get
cos(90-b)= cos 90 cos b + sin 90 sin b
Value of cos 90 = 0 and sin 90 =1 , And on using these values, we will get
cos(90-b) = (0) cos (b) + (1) sin (b)
cos(90-b) = 0 + sin (b)
cos(90-b) =sin(b)
As we see that on using the formula, we are getting cos(90-b)= sin b .
So the correct option is cos(90-b)= sin b
x + y = -9
x + 2y = -25
Rewrite the first equation as x = -9-y
Relace x in the second equation:
-9-y + 2y = -25
Simplify:
-9 +y = -25
Add 9 to both sides:
y = -16
Now you know y,, replace y in the first equation and solve for x:
x -16 = -9
Add 16 to both sides:
x = 7
Answer: x = 7
Answer:
The interest rate of the account is
Step-by-step explanation:
we know that
The compound interest formula is equal to
where
A is the Final Investment Value
P is the Principal amount of money to be invested
r is the rate of interest in decimal
t is Number of Time Periods
n is the number of times interest is compounded per year
in this problem we have
substitute in the formula above and solve for r
Convert to percent
So for this one all you have to do is find the average. Simply do 25 divided by 2 to get 12.5 miles per hour.
What is the actual question here? I'm not sure if I'm just reading over it but it's not clear