Need Help With Math Problem!
06-23-2003, 07:48 PM
#41
Junior Member
Join Date: Nov 2002
Location: Cedarville NJ
Posts: 16
06-23-2003, 10:11 PM
#48
Senior Member
Join Date: Mar 2002
Location: Gulf Breeze, FL; ATL, Ga; Bucyrus, Oh
Posts: 1,960
Originally Posted by ROTARYROCKET7' date='Jun 23 2003, 10:00 AM
AN interger is non negative because it lies in the set of real numbers. If you go into negative numbers with intergers you are now entering the set of imaginary numbers. Those problems are brain teasers and the way to solve it by trial and error using odd and even numbers. I just failed my math test for Differential Equations.
SOlve this problem:
x^2 means x squared okay..
y' means first derivative.. '' means second and so on
e= eulers equation = 2.7
ln= natural log
cos t^2 + sin t^2 =1 ( identity)
cot = cotangent
sec= secant
IIGht
Find a Particular Solution for
y'' + 4y= 3 csc t ( csc is the cosecant so its 1/sin (t) )
SO the general solution is yc(t) = C1 cos 2t + C2 sin2t
The general solution is off this form because the discriminat b2-4ac ( part of the quadratic equation of the form -b +- (b2-4ac)^(1/2) / 2(a) ). is less than 0. so then the general equation is y= e ^ lambda (t) ( c1 cos u(t) + c2 sin u(t) ) and the discrimant therfore gives us lambda = 0 so e raised to the zero is 1 and then we get C1 cos 2t + C2 sin2t.
Find the coefficiants c1 and c2 byusing variation of parameters where the first condition that needs to be satisfied is
1) v1'y1 + v2'y2= 0
2) v1'y1' + v2'y2' = csc (t) by using trigonometric substituition. Engineers of NP.com gimme this answer!
The answer is y= 3 sint + 3/2 ln | csc t - cot t|sin2t + c1 cos2t + c2 sin2t
SOlve this problem:
x^2 means x squared okay..
y' means first derivative.. '' means second and so on
e= eulers equation = 2.7
ln= natural log
cos t^2 + sin t^2 =1 ( identity)
cot = cotangent
sec= secant
IIGht
Find a Particular Solution for
y'' + 4y= 3 csc t ( csc is the cosecant so its 1/sin (t) )
SO the general solution is yc(t) = C1 cos 2t + C2 sin2t
The general solution is off this form because the discriminat b2-4ac ( part of the quadratic equation of the form -b +- (b2-4ac)^(1/2) / 2(a) ). is less than 0. so then the general equation is y= e ^ lambda (t) ( c1 cos u(t) + c2 sin u(t) ) and the discrimant therfore gives us lambda = 0 so e raised to the zero is 1 and then we get C1 cos 2t + C2 sin2t.
Find the coefficiants c1 and c2 byusing variation of parameters where the first condition that needs to be satisfied is
1) v1'y1 + v2'y2= 0
2) v1'y1' + v2'y2' = csc (t) by using trigonometric substituition. Engineers of NP.com gimme this answer!
The answer is y= 3 sint + 3/2 ln | csc t - cot t|sin2t + c1 cos2t + c2 sin2t
06-24-2003, 11:40 AM
#49
Senior Member
Join Date: Dec 2002
Location: QUEENS NYC
Posts: 1,687
Yo freestyle reaction i got something for you. Or anyone else solve these basic math problems.
1). iight what is e raised to the natural log of x squared?
2). whats the Intergral of sin x?
3) what is the derivative of (4x sqaured + 5) squared?
4.) what is the half angle formula for cos squared x.?
These are basic ****. YEah u can look up these identities behind your math book. lol.
Yeah intergers are negative my bad but i dont consider them negative cause when ever we use intergers we never really use em with the negatives well at least in my math study. we just say non-zero or something to denote that they are all positives.
I hate imaginary numbers which are the +- of a square root..
***********BONUS*************
For all you smartees
What is the Partial Derivative of F(x,Y) = 3x^2 + xy + 2x^2y^3..
find Fx, Fy, and Fxy....
1). iight what is e raised to the natural log of x squared?
2). whats the Intergral of sin x?
3) what is the derivative of (4x sqaured + 5) squared?
4.) what is the half angle formula for cos squared x.?
These are basic ****. YEah u can look up these identities behind your math book. lol.
Yeah intergers are negative my bad but i dont consider them negative cause when ever we use intergers we never really use em with the negatives well at least in my math study. we just say non-zero or something to denote that they are all positives.
I hate imaginary numbers which are the +- of a square root..
***********BONUS*************
For all you smartees
What is the Partial Derivative of F(x,Y) = 3x^2 + xy + 2x^2y^3..
find Fx, Fy, and Fxy....
06-24-2003, 01:55 PM
#50
Junior Member
Join Date: Oct 2002
Location: calgary
Posts: 28
1. x=2e ???
2. 0 or -cosx i am pretty sure zero
3. 2(4x+5)(8x) = 64x^2 + 80x
4. can't remember
does the bonus want implicit differentiation? i haven't seen a question worded like that. i only took high school calculus
anyways implicit differentiation gives us y' = (-6x - 6x2y^3) / (x + 6y^2 2x^2)
2. 0 or -cosx i am pretty sure zero
3. 2(4x+5)(8x) = 64x^2 + 80x
4. can't remember
does the bonus want implicit differentiation? i haven't seen a question worded like that. i only took high school calculus
anyways implicit differentiation gives us y' = (-6x - 6x2y^3) / (x + 6y^2 2x^2)