First, you have to find the LCD. The LCD of 4 and 7 is 28, so you rewrite the fraction:
7/28
4/28
Then you add them.
Answer:
Step-by-step explanation:
$9.87
- <u>2.81</u>
$7.06 Jenny has left
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.

Answer:
y = 120°
Step-by-step explanation:
angles in a triangle add up to 180 degrees
180 - (87 +33) = 60
x = 60 degrees
angles on a straight line add up to 180 degrees
180 - 60 = 120
y = 120
H = -5t^2 +5t + 10
a) t = 0, h = 10 at time 0
b) h = (-5t + 10) ( t + 1)
c) put 0 in for the height and set each factor = to 0 and solve each
0 = (-5t + 10) and 0 = (t + 1)
solve each t = 2 and t = -1, so t = 2 sec is your solution
d) because a parabola is symmetric, the max will be half way between -1 and 2, at t = 1/2
h = -5(1/2)^2 +5(1/2) + 10
h = -5(1/4) + 5/2 +10
h = -5/4 + 5/2 + 10
h = -5/4 + 10/4 + 40/4
h = 45/4