Math Flashcards
Hyperbola Equation
Ax2+2Bxy+Cy2+…=0
B2-AC>0
Cos2θ+sin2θ
2Cosθ*sinθ
1
2sinθ
Adjoint
adj|2 3|
|-1 0|
|0 -3|
|1 2|
Eigenvalues
|1 1|
|2 0|
|1-λ 1|
|2 0-λ|
Particular Differential Equation
y+4y=3e^(-t)
replace y to solve the equation
y=Ae^(-t)
Amplitude
of steady-state
y+4y+4y=8sin2t
replace y with some comon factor
yp=Asin2t+Bcos 2t
Volume of a parabola
V=∫πx2dy ,0,a
the vector field is conservative is zero
The curl
the curl of a vectore field is zero if it is conservative
the cross product AxB
A= (4i+2j)
B= (3i+5j)
(4*5)- (2*3)
Dot Product
A*B
A=(4i+2j)
B(3i+5j)
A*B= (4*3)+(2*5)
component of A in the direction B
A=i-4j and B= 2i-4j-4k
A*iB=(A*B)/|B|
={(i-4j)*(2i-4j-4k)]
(22+42+42)1/2
(2+16)/6=3
the diferential equation
y”+3x2y’+sinx=0
is?
x: nonhomogeneous
X2: variable coefficient
depends in Y:linear
if its in terms of Y will be nonlinear
Taylor series
Cos2x
1-(2x)2/2!+(2x)4/4!-….
intercept of the line tangent to the parabola
x=2y2
point: (2,1)
derivada de x
x=4y
y=1/4x+b
replce the point and find b
i=
i=e(πi/2)