## Questions by Sun from Los Angeles, CA

Find the curvature at the point (x, y) on the ellipse x^2/9+y^2/4=1.   x^2/a^2+y^2/b^2=1 x(t)=acos(t) y(t)=bsin(t) x(t)=3cos(t) y(t)=2sin(t) ---------------------------- k=abs(x'y"-y'x")/[(x')^2+(y')^2]^(3/2) k=6/(9sin^2...

A stone weighing 1/2 lb is thrown upward from an initial height of 5 ft with an initial speed of 32 ft/s. Air resistance is proportional to speed, with k=1/128 lb-s/ft. Find the maximum height attained...

A constant horizontal force of 10N pushes a 20kg-mass through a medium that resists its motion with 0.5N for every m/s of speed. The initial velocity of the mass is 7 m/s in the direction opposite...

Find the general solution of xy'+(ln x)y=0.   Answer: y=ce^(-(ln x)^2)/2   Please show all your work step by step. And tell me the input on Ti-89 for this problem to...

Solve the initial-value problem y'''=(x^2)(e^x), y(0)=1, y'(0)=-2, y"(0)=3.    Answer: y=(x^2-6x+12)e^x+x^2/2-8x-11   Please show all your work step by...

Solve the differential equation y"+y'=e^t.    Please show all your work step by step and tell me the right answer. Also tell me how to find the answer for this problem on...

Solve the differential equation y"+y'=e^t.   Please show all your work step by step and tell me the right answer.

Find the limit of y(t) as t approaches infinity for the initial value problem   y'=sin(y(t)), y(0)=pi/2.   The answer is pi. Please show all your work step by step. Thanks...

Use exact arithmetic to solve the following system:   10-3x-y=1, x+y=0.   The book says the answer is (1/1.001, -1/1.001). Please show all your work step by step...

Use 3-digit arithmetic with partial pivoting to solve the following system:   10-3x-y=1, x+y=0.   The book says the answer is (1, -1). Please show all your work step...

Use 3-digit arithmetic with no pivoting to solve the following system:   10-3x-y=1, x+y=0.   The book says the answer is (0, -1). Please show all your work step by...

Use Gaussian elimination with back substitution to solve the following system:   x1+x2+x3=1, x1+2x2+2x3=1, x1+2x2+3x3=1.   The answer is (1,...

Can anyone please recommend me a good textbook for Linear Algebra that has lots of practice problems and less theoretical problems?

Can you please recommend me a good textbook for the course "Complex Variables with Applications"?

Is the course "Complex Variables with Applications" the course taken after Differential Equations? What does this course cover? Is this course applied or pure math? Can someone recommend...

Is "Advanced Math for Engineers" a course taken after Differential Equations for engineering students at college? What does this course cover? Is it useful for computer programmers? Can...