help please (1 Viewer)

[SEAKING]

i have a maths test on tues someone help lulz

 

[RedZenith]

(a) What's tha eccentricity

(b) '' '' ''

(c) ASS = pi(5.5^2-2.5^2)

(d) not clear enough

(e) ASS = 80/360 * pi(10^2-7^2)

(f) 1. APA = 9*5 - (4.2*2.2 + 2*pi(2.2)^2)
2. TCOP = 34.90 * (APA)

 

[SEAKING]

thanks for e.

 

[jirwin]

a) pi x 1.4 x 3.9 = 17.15309589 = 17.1 (1dp)
b) (8 x 15) - (pi x 4 x 7.5) = 25.75222039 = 25.8 (1dp)
c) pi(5.5^2-2.5^2) = 75.39822369 = 75.4 (1dp)
d) sorry no idea.
e) 80/360pi(10^2-7^2) = 35.60471674 = 35.6 (1dp)
f) (9 x 5) - ((4.2 x 2.2) + (pi x 1.1^2)) (theres 2 semi circles so only need to do 1 total circle. u also need to divide 2.2 in order to get the radius. redzenith did two circle and didnt divide it.

 

[yosemite sam]

wouldnt e be pi 15^2 - pi 7.5^2

 

[Mark576]

(d) is drawn terribly, it seems as if it's supposed to represent two circles, the unshaded circle having a diameter of 15mm. If so it's simple to find the area of the shaded region, just use A = pi ( R^2 - r^2), where R and r are the respective radii of the larger and smaller circle.