Π radians = 180°
5 π / 4 = 5 · 180° / 4 = 900° / 4 = 225°
cos ( 5π/4 ) = cos 225°
With the unit circle we can find the exact value:
cos 225° = - √2 / 2 ≈ - 0.7071
To calculate the length of the diagonal, use the Pythagorean theorem:
c^2 = a^2 + b^2, where c is the diagonal.
c^2 = 65^2 + 34^2
c^2 = 4225 + 1156
c^2 = 5381
c ~ 73.36
To the nearest tenth of a meter, the diagonal has a length of 73.4 m
1000m equals 1km so 600m equals 0.6km.
Question 5:
the circumference is given by:
C = 2 * pi * r
Where,
r: radio of the ball
Substituting values we have:
22 = 2 * pi * r
Clearing r we have:
r = 11 / pi
The surface area is given by:
A = 4 * pi * r ^ 2
Substituting values we have:
A = 4 * 3.14 * (11 / 3.14) ^ 2
A = 154 in ^ 2
Answer:
The surface area of the balloon is:
A = 154 in ^ 2
Question 8:
For this case we have that the scale factor is given by:
V1 = (k ^ 3) * V2
Substituting values we have:
729 = (k ^ 3) * 2744
Clearing k:
k = (729/2744) ^ (1/3)
k = 9/14
Answer:
the scale factor of a cube with volume 729 m ^ 3 to a cube with volume 2,744 m ^ 3 is:
9:14
Question 2:
The volume of the cylinder is given by:
V = pi * r ^ 2 * h
Where,
r : radio
h: height
Substituting values:
V = pi * (2.8) ^ 2 * (13)
V = 101.92 * pi
Answer:
The volume of the cylinder is:
V = 101.92 * pi
option 3
