Answer:
Pythagorean's theorem: a²+ b²= c²
Sines: sin A = a/c, sin B = b/c.
Cosines: cos A = b/c, cos B = a/c.
Tangents: tan A = a/b, tan B = b/a.
Step-by-step explanation:
For example, if the side a = 22 and the angle A = 41°, we can use a sine and a tangent to find the hypotenuse and the other side. Since sin A = a/c, therefore c = a/sin A = 22/sin 41. Using a calculator, this is 22/0.6561 = 33.5314. Also, tan A = a/b, so b = a/tan A = 22/tan 41 = 22/0.8693 = 25.307.
The correct answer is the last one
(0,-4)
Answer:
h ≈ 7.816 cm
r ≈ 5.527 cm
Step-by-step explanation:
The volume of a cone is:
V = ⅓ π r² h
The lateral surface area of a cone is:
A = π r √(r² + h²)
1/4 of a liter is 250 cm³.
250 = ⅓ π r² h
h = 750 / (π r²)
Square both sides of the area equation:
A² = π² r² (r² + h²)
Substitute for h:
A² = π² r² (r² + (750 / (π r²))²)
A² = π² r² (r² + 750² / (π² r⁴))
A² = π² (r⁴ + 750² / (π² r²))
Take derivative of both sides with respect to r:
2A dA/dr = π² (4r³ − 2 × 750² / (π² r³))
Set dA/dr to 0 and solve for r.
0 = π² (4r³ − 2 × 750² / (π² r³))
0 = 4r³ − 2 × 750² / (π² r³)
4r³ = 2 × 750² / (π² r³)
r⁶ = 750² / (2π²)
r³ = 750 / (π√2)
r³ = 375√2 / π
r = ∛(375√2 / π)
r ≈ 5.527
Now solve for h.
h = 750 / (π r²)
h = 750 / (π (375√2 / π)^⅔)
h = 750 ∛(375√2 / π) / (π (375√2 / π))
h = 2 ∛(375√2 / π) / √2
h = √2 ∛(375√2 / π)
h ≈ 7.816
Notice that at the minimum area, h = r√2.
Answer:
-4
Step-by-step explanation:
distributing gets you to : 8h + 38 = -18 - 6h
then add 6h to 8h and you have 14h + 38 = -18
solve normally & thats how you get your answer
