Answer:
y = 2cos5x-9/5sin5x
Step-by-step explanation:
Given the solution to the differential equation y'' + 25y = 0 to be
y = c1 cos(5x) + c2 sin(5x). In order to find the solution to the differential equation given the boundary conditions y(0) = 1, y'(π) = 9, we need to first get the constant c1 and c2 and substitute the values back into the original solution.
According to the boundary condition y(0) = 2, it means when x = 0, y = 2
On substituting;
2 = c1cos(5(0)) + c2sin(5(0))
2 = c1cos0+c2sin0
2 = c1 + 0
c1 = 2
Substituting the other boundary condition y'(π) = 9, to do that we need to first get the first differential of y(x) i.e y'(x). Given
y(x) = c1cos5x + c2sin5x
y'(x) = -5c1sin5x + 5c2cos5x
If y'(π) = 9, this means when x = π, y'(x) = 9
On substituting;
9 = -5c1sin5π + 5c2cos5π
9 = -5c1(0) + 5c2(-1)
9 = 0-5c2
-5c2 = 9
c2 = -9/5
Substituting c1 = 2 and c2 = -9/5 into the solution to the general differential equation
y = c1 cos(5x) + c2 sin(5x) will give
y = 2cos5x-9/5sin5x
The final expression gives the required solution to the differential equation.
Answer:
D
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Subtract the sum of the 2 given angles from 180
x = 180° - (90 + 35)° = 180° - 125° = 55°
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Since the triangle is right use the cosine ratio to solve for b
cos35° =
= 
Multiply both sides by 20
20 × cos35° = b, hence
b = 16.38 ( to 2 dec. places )
Answer:
Outside the circle
Step-by-step explanation:
Let's first write the equation of this circle:
, where (h, k) is the center and r is the radius. Here, the center is (-6, -2). We need to find the radius, which will just be the distance from N to E:
NE = 
The radius is √34, which means that r² = 34. So, our equation is:
(x + 6)² + (y + 2)² = 34
Plug in -10 for x and -7 for y:
(x + 6)² + (y + 2)² = 34
x² + 12x + 36 + y² + 4y + 4 = 34
x² + 12x + y² + 4y + 40 = 34
x² + 12x + y² + 4y + 6 = 0
(-10)² + 12 * (-10) + (-7)² + 4 * (-7) + 6 = 7
Since 7 > 0, we know that H lies outside the circle.
Answer:
- (2^9)
Step-by-step explanation:
-(2^6)(2^3)
We know a^b * a^c = a^( b+c)
- ( 2 ^ (6+3))
- (2^9)