Answer:
Step-by-step explanation:
Since this is not a right triangle, we will use the Law of Sines. For us that looks like this:
and cross multiply to get
4sin55 = 3.5sinx and solve for sinx:
so
sinx = .9361737 Use the 2nd button on your calculator and the sin button to find that the angle
x = 69.4°. Not sure how you need it rounded. It's actually 69.4186°
Answer:
CE = 17
Step-by-step explanation:
∵ m∠D = 90
∵ DK ⊥ CE
∴ m∠KDE = m∠KCD⇒Complement angles to angle CDK
In the two Δ KDE and KCD:
∵ m∠KDE = m∠KCD
∵ m∠DKE = m∠CKD
∵ DK is a common side
∴ Δ KDE is similar to ΔKCD
∴
∵ DE : CD = 5 : 3
∴
∴ KD = 5/3 KC
∵ KE = KC + 8
∵
∴
∴
∴
∴
∴ KC = (8 × 9) ÷ 16 = 4.5
∴ KE = 8 + 4.5 = 12.5
∴ CE = 12.5 + 4.5 = 17
For each <em>x</em> in the interval 0 ≤ <em>x</em> ≤ 5, the shell at that point has
• radius = 5 - <em>x</em>, which is the distance from <em>x</em> to <em>x</em> = 5
• height = <em>x</em> ² + 2
• thickness = d<em>x</em>
and hence contributes a volume of 2<em>π</em> (5 - <em>x</em>) (<em>x</em> ² + 2) d<em>x</em>.
Taking infinitely many of these shells and summing their volumes (i.e. integrating) gives the volume of the region:
