Answer: x=2π/3 and x=4π/3
Step-by-step explanation:
The equation we have is . All we have to do is get cosine alone to find the 2 values of x.
Now that we have our cosine left, we can use our unit circle to figure out when does cosx=-1/2. Cosine is the x value of the coordinate.
x=2π/3
x=4π/3
Answer: There are 97 nickels and 108 quarters.
Step-by-step explanation:
Let x = Number of nickels, y = Number of quarters.
As per given,
x+y = 205 ...(i)
0.05x+0.25y = 31.85 ... (ii) [1 nickel = $0.05, 1 quarter = $ 0.25]
Multiply (ii) by 20, we get
x+5y=637 ...(iii)
Eliminate (i) from (iii)
4y = 432
⇒ y = 108 [Divide both sides by 4]
Put value of y in (i), we get
Hence, there are 97 nickels and 108 quarters.