Answer with Explanation:
Keep in mind these trigonometric Identity:
1. Cos²x - Sin² x= Cos 2 x
2. Cos 2 x = 2 Cos²x-1
3. Cos 2 x = 1 - 2 Sin²x
Now, Coming to the Problem
1 + Cos (18 x)
= 1 + Cos (2 × 9 x)
= 2 Cos ² (9 x)→→→ Cos (2 × 9 x)= 2 Cos² (9 x) - 1
3(k + 1) + 5k = -1 +5(k-1)
- 35
3k+3+5k= -1+5k-5-35
3k-5k+5k= -1-5-3-35
3k=-44
k= -14.6
Answer:
<u>Step-by-step explanation:</u>
The power rule is "multiply the exponents".
You must understand that the exponent of both h and g is 1.
Multiply 1 times 9 for both variables.
The slope is the change in Y divided by the change in X.
You would need to know the coordinates of 2 points ( X1,Y1) and (X2,Y2), then subtract : Y2 - Y1 divided by X2- X1.
If altogether they spent a total of $71, and a cap cost $5, then the price of a t-shirt is $8. Option A is correct
From the question, we are told that all caps cost $5 each
Let the cost of each shirt be x:
If Andy bought a t-shirt and a cap for each of his six friends, there will be 6 shirts and 6 caps
If <u>Bob returned two caps and two t-shirts</u>, there will be 4 caps and 4 shirts left
If <u>Carl bought three t-shirts and returned a cap,</u> the number of caps remaining will be 3 caps and the number of shirts remaining will be 7 shirts
If they spent a total of $71, this means;
3(5) + 7x = 71
15 + 7x = 71
7x = 71 - 15
7x = 56
x = 56/7
x = 8
This shows that the price of a t-shirt is $8
Learn more here: brainly.com/question/16510024