Answer: see proof below
<u>Step-by-step explanation:</u>
Use the Sum & Difference Identity: cos (A + B) = cos A · cos B - sin A · sin B
Recall the following from Unit Circle: cos (π/2) = 0, sin (π/2) = 1
cos (π) = -1, sin (π) = 0
Use the Quotient Identity: 
<u>Proof LHS → RHS:</u>
Quotient: tan x
LHS = RHS 
Answer:
$13,200
Step-by-step explanation:
You need to use the simple interest formula
I = P * r * t
I = Interest accrued
P = Principal amount invested
r = Interest rate you need to divide by 100 to get it in decimal form
t = time, in years if you are given a partial year, divide the months by 12
P = $12,000
r = 7.5% = .075
t = 1
But, because we want I to equal $990 then I is
I = $990
So we ignore our P and instead solve for the P that will give us the desired result.
I = P * r * t
$990 = P * .075 * 1
$990 = P.075 Divide each side by .075
$990/.075 = P.075/.075
$990/.075 = P
$13,200 = P
So, to earn an annual interest income of $990, $13,200 will have to be invested in the 7.5% bond.
Step-by-step explanation:
A
The probability of wining is 1/4 so it's 25%. so if you win you either win one of 2 object, so we have to divide the chance of wining by the number of object, so (25%)/2
A it's ,12.5% chance of wining the mug
B yes, it will change if she pics the mug first, it will be 25% because it's guaranteed that she will get the mug if she wins
3 + [_] ÷ 7 = 9
[_] ÷ 7 = 9 - 3
[_] = 6 x 7
[_] = 42
to check, just put 42 in the empty place and solve
