deel
Most popular questions and responses by deel
math
The stiffness S of a rectangular beam is proportional to its width (w) times the cube of its depth/height (h). find the dimensions (i.e.: w and h) of stiffest beam that can be cut from a log which has a circular crosssection with diameter of 12in.
asked on August 9, 2012 
math
Please help me to find an equation for the tangent to the curve xsin2y=ycos2x at the point (phi/4, phi/2)
asked on August 13, 2012 
math
In a room of 20.000 ft^3 of air, 600 ft^3 of fresh air flows in per minute, and the mixture (made practically inform by circulating fans) is exhausted at a rate of 600 cubic feet per minute (cfm). What is the amount of fresh air inside the room y(t) at any
asked on August 8, 2012 
math
A tank contains 50 gallons of a solution composed of 90% water and 10% alcohol. A second solution containing 50% water and 50% alcohol is added to the tank at rate of 4 gallons per minute. As the second solution is being added, the tank is being drained at
asked on August 10, 2012 
math
A right circular cylinder of radius r and height h is inscribed in a right circular cone of radius R and height H, as shown on the right figure. Find the value of r (in terms of R and H) that maximizes the total surface area of the cylinder (including top
asked on August 11, 2012 
math
how to find the following limit : lim lnx/lgx x>infinity
asked on August 21, 2012 
math
find the derivatives, dy/dx for the folowing function : y=ln(cos(0.5)+(sin(x^2+3))^1/3)
asked on August 25, 2012 
math
find the derivatives, dy/dx, for the following functions : y=(1+sin^2{2 exp (3x)})^5y please help me to solve this assignment. thank's
asked on August 20, 2012 
math
please help me how to solve the integral sinx/x dx from 0 to infinite : ∫_0^∞▒〖sinx/x dx〗 thank you
asked on March 24, 2013 
math
consider a 2D mirror has a parabolic profile of y = (x3)^2 + 5 facing toward y^+ direction. Prove that any beam of light in y^ direction that this hits the mirror will be reflected toward a particular point (i.e. known as the focus of parabolic mirror.
asked on September 17, 2012 
linear algebra
in order to grow a certain crop, it is recommended that each square foot of ground be treated with 10 units of phosphorous, 9 units of potassium, and 19 units of nitrogen, suppose that there are three brands of fertilizer on the market  say brand X, brand
asked on November 11, 2012 
math
please help me to solve this assignment : consider a 2D mirror has a parabolic profile of y = (x3)^2 + 5 facing toward y^+ direction. Prove that any beam of light in y^ direction that this hits the mirror will be reflected toward a particular point (i.e.
asked on September 18, 2012

math
thank's steve :)
posted on August 21, 2012 
math
yes i'm sure..the assignment like that.
posted on August 20, 2012 
math
thanks for your help :)
posted on August 11, 2012 
math
y(t)=amount of alcohol in the tank at time t dy/dt =y’(t) = alcohol inflow rate – alcohol outflow rate = 4  5(y/50) =200  5y/50 = 5 (40y)/50 dy/dt = 5 (40y)/50 Separate variable and integrate : dy/(40y) = 5/50dt ln(40y) = 0.1t + C ln(40y)
posted on August 11, 2012 
math
oke thanks, i'ill try it
posted on August 11, 2012 
math
thanks for your help
posted on August 10, 2012 
math
yes i understand now, thanks for your help
posted on August 9, 2012 
math
thanks for your help
posted on August 9, 2012 
math
h^3=s/kw h^3=s/k(12h) sorry, I'm still confused how to get the function of h. please help me to complete the assignment. thank you
posted on August 9, 2012