Answer:
10 or -10,
Read the explanation
Step-by-step explanation:
Rewrite this problem as a numerical expression. As per the wording of this problem, there can be two expressions derived.
1. 
2. 
Simplify, remember the order of operations. The order of operations is the sequence by which one is supposed to perform operations in a numerical expression. This order is the following:
1. Parenthesis
2. Exponents
3. Multiplication or division
4. Addition or Subtraction
Use this sequence when simplifying and solving the expression:
Expression 1
Expression 2
It is not factorable. Factors of 21 are. 21 and 1
7 and 3. None of those add up to 12
6.) triangles; 6 units
7.) 5 x 6; 30 units
8.) 72 units
9.) 84 units
Hope this helps!
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)
The magnification factor is given as
. Therefore multiplying this by the spider's actual length will give its apparent length.
This gives an apparent length of 12,000 mm.
Since 1,000 mm = 1 m, this apparent length is also equivalent to 12 m.
