We are to verify the identity:
cos(α-B)-cos(α+B) = 2 sinα sinβ
Left hand side = cos(α - B)-cos(α + B)
= cosα cosβ + sinα sinB - (cosα cosB - sinα sinβ)
= cosα cosβ + sinα sinB - cosα cosB + sinα sinβ)
= sinα sinβ + sinα sinβ
= 2 sinα sinβ
= Right Hand side
The answer is probably 50 ok
3/4x-12-5=15
3/4x-17=15
3x-68=60
3x=60+68
3x=128
X=128/3
Answer: $3,664.21
Formula: 
- P = principle/original amount = $3000
- r = rate of interest = 4% = 0.04
- t = time period (in years) = 5
- A = the new amount
- e = Euler's number ≈ 2.718...
Substitute in the values:

<u>Approximately $3,664.21</u>
<em>I think this is how you solve it o_O</em>