Answer:
Step-by-step explanation:
cot²(3x)=y
y²-3y+2=0
y²-y-2y+2=0
y(y-1)-2(y-1)=0
(y-1)(y-2)=0
y=1,y=2
cot3x=1
tan 3x=1=tan (π/4)=tan (nπ+π/4)
3x=nπ+π/4=(4nπ+π)/4=(4n+1)π/4
x=(4nπ+1)π/12,n is an integer.
cot 3x=2
tan 3x=1/2
3x=tan^{-1}(1/2)≈26.57°+360n
x≈8.86°+120n
Answer:
$7.81
Step-by-step explanation:
To solve, subtract the amount given to you ($20) with the amount you need ($12.19).
20 - 12.19 = 7.81
You will need to give $7.81 to the customer.
~
Answer:
$2,520
Step-by-step explanation:
The simple Interest earned on an deposit, P at a rate of r% for a period of t years is calculated using the formula:
P=$10,500
R=6%
T=4 years
Therefore:
Sally will earn $2520 interest after 4 years.
Answer:
x squared over 4 plus y squared over 8 equals 1
Step-by-step explanation:
The general equation of ellipse is given as;
(x²/a²) + (y²/b²) = 1
The coordinates of a foci are: (±c, 0) where;
c² = b² - a²
However, we know that equation of directrix is; x = ±a/e
Now, Directrix is given ±4
Thus, a/e = 4
a = 4e
We also know that c = ae from ellipse foci coordinates.
Thus, ae = 2
since ae = 2, then (4e)e = 2
4e² = 2
e² = 2/4
e = 1/2
Thus;
a = 4 × 1/2
a = 2
Since c² = b² - a²;
2² = b² - 2²
4 = b² - 4
b² = 8
From (x²/a²) + (y²/b²) = 1, we can put our values to get;
x²/4 + y²/8 = 1
Answer:
He needs 3 customers.
Step-by-step explanation:
$48/$16 = 3
He needs 3 customers.