Answer:
63.5
Step-by-step explanation:
The diagonals of a rhombus bisect opposite angles.
The longer diagonal bisects the 42° angle
The larger angle of the rhombus is 180 - 42 = 138
Let x = the length of the longer diagonal
You know two sides and the included angle of a triangle.
Using the law of cosines we get
x^2 = 34^2 + 34^2 - 2(34)(34) cos 138
= 1156 + 1156 - 2312 c0s 138
= 4030.1508...
x = sq rt 4030.1508...
= 63.5
Since a small drink is the cheapest, make the cost of a small drink=x. Since a large drink costs 50 cents more than a small drink, let a large drink=x+50. The total of the drinks is the sum of the individuals. Since the cost of a small drink is x, 3 drinks cost 3x. Since the cost of a large drink is x+50, the cost of 2 drinks is 2(x+50). The cost of all of the drinks together is 3x+2(x+50). Distribute the 2. 3x+2x+100. Combine like terms. 5x+100. This will give you your answer in cents. If you need an answer in dollars, you multiply that expression by 0.01.
We know that
1) Sandra can run a mile in 6 minutes-------> 6*60-----> 360 sec
2) 4 laps around the track equals 1 mile
so
4 laps around the track in 360 sec
1 lap in 360/4--------> 90 sec
3) the position of Sandra for t=90 sec must be equal to the point S (0,56)
I proceed to analyze each case for t=90 sec
case a) x(t)=-140 cos(pi*t/45) y(t)=112 sin(pi*t/45)
x(t)=-140 cos(pi*90/45)------> -140
y(t)=112 sin(pi*90/45)-------> 0
the position is the point (-140,0)------> is not the point S
case b) x(t)=140 sin(pi*t/90) y(t)=-112 cos(pi*t/90)
x(t)=140 sin(pi*90/90)------> 0
y(t)=-112 cos(pi*90/90)-------> 112
the position is the point (0,112)------> is not the point S
<span>
case c) x(t)=-70 sin(pi*t/45) y(t)=56 cos(pi*t/45)
</span>x(t)=-70 sin(pi*90/45)------> 0
y(t)=56 cos(pi*90/45)
-------> 56
the position is the point (0,56)------> is equal to the point S----> is the solution
case d) x(t)=70 cos(pi*t/90) y(t)=-56 sin(pi*t/90)
x(t)=70 cos(pi*90/90)------> -70
y(t)=-56 sin(pi*90/90)-------> 0
the position is the point (-70,0)------> is not the point S
therefore
the answer is the option C
x(t)=-70 sin(pi*t/45) y(t)=56 cos(pi*t/45)
Answer:
9.830
Step-by-step explanation:
I'm not sure if it's right but hope this helps you
