Answer
X-2y = 2
3x + y = 6
Ox=-2
Ox=0
Ox=2
Ox=3
= 0
Step-by-step explanation:
easy
Answer:
72.83
Step-by-step explanation:
61²+x²=95²
3721+x²=9025
x²=<u> </u><u>530</u><u>4</u>
<u>x</u><u>=</u><u> </u><u>72.83</u>
Answer:
Step-by-step explanation:
A)
"In the last 2.5 years, the water level has decreased 0.75 feet."
In the very first statement it has been stated that over the last 2.5 years, the water level in a lake has changed by -0.3 feet per year. That means in the last 2.5 years , total decrease in level is as follows
2.5 x - 0.3 = - .75 ft .
So the statement is true.
B)
"The overall change of the water level after 7.5 years will be -2.75 feet."
This statement appears to be false based on information provided
No prediction regarding rate of decrease for a period beyond 5 year has been made so any statement with respect to a timeline of 7.5 years may turn out to be false.
C)
"The change in water level each year for the next 5 years will be -0.4 feet.
"
This statement prima-facie appears to be true because rate of decrease stated in the statement is 0.4 ft /year for next 5 years .
D )
"The overall change in water level for the next 5 years is equal to 5(0.4)"
this statement is true
as change in one year = .4
change in 5 years = 5 x .4
Givens
y = 2
x = 1
z(the hypotenuse) = √(2^2 + 1^2) = √5
Cos(u) = x value / hypotenuse = 1/√5
Sin(u) = y value / hypotenuse = 2/√5
Solve for sin2u
Sin(2u) = 2*sin(u)*cos(u)
Sin(2u) = 2(
) = 4/5
Solve for cos(2u)
cos(2u) = - sqrt(1 - sin^2(2u))
Cos(2u) = - sqrt(1 - (4/5)^2 )
Cos(2u) = -sqrt(1 - 16/25)
cos(2u) = -sqrt(9/25)
cos(2u) = -3/5
Solve for Tan(2u)
tan(2u) = sin(2u) / cos(2u) = 4/5// - 3/5 = - 0.8/0.6 = - 1.3333 = - 4/3
Notes
One: Notice that you would normally rationalize the denominator, but you don't have to in this case. The formulas are such that they perform the rationalizations themselves.
Two: Notice the sign on the cos(2u). The sin is plus even though the angle (2u) is in the second quadrant. The cos is different. It is about 126 degrees which would make it a negative root (9/25)
Three: If you are uncomfortable with the tan, you could do fractions.
