Answer:
y = x*sqrt(Cx - 1)
Step-by-step explanation:
Given:
dy / dx = (x^2 + 5y^2) / 2xy
Find:
Solve the given ODE by using appropriate substitution.
Solution:
- Rewrite the given ODE:
dy/dx = 0.5(x/y) + 2.5(y/x)
- use substitution y = x*v(x)
dy/dx = v + x*dv/dx
- Combine the two equations:
v + x*dv/dx = 0.5*(1/v) + 2.5*v
x*dv/dx = 0.5*(1/v) + 1.5*v
x*dv/dx = (v^2 + 1) / 2v
-Separate variables:
(2v.dv / (v^2 + 1) = dx / x
- Integrate both sides:
Ln (v^2 + 1) = Ln(x) + C
v^2 + 1 = Cx
v = sqrt(Cx - 1)
- Back substitution:
(y/x) = sqrt(Cx - 1)
y = x*sqrt(Cx - 1)
Step-by-step explanation:
the law of sines :
a/sin(A) = b/sin(B) = c/sin(C)
with the sides being opposite to the angles.
so,
14/sin(80) = x/sin(60)
x = 14×sin(60)/sin(80) ≈ 12.3cm
Answera A
Step-by-step explanation:
Answer:
1/3 of 45 = 15 cubic feet
Step-by-step explanation:
volume of rectangular prism = (B)(h)
volume of rectangular pyramid = 1/3(B)(h)