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visits member for 3 years, 9 months
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Started programming on a ZX spectrum in the 80's and have moved through Assembly, Turbo Pascal, C++, C#, Fortran. My main area of focus is engineering and scientific computing like numerical methods and 3D graphics.


11h
comment Determine the general solution for $2\cos^2x-5\cos x+2=0$
Use \cos x instead of \rm{cos} x and use \mbox{..} for text within math (if needed).
2d
comment How to find a vector normal to a cylinder in cylindric coordinates?
This question appears to be off-topic because it a simple search can yield the answer. See en.wikipedia.org/wiki/…
Aug
26
comment At the instant of release of an object from rest. Is the only force that can act its weight?
Can you explain the significance of A1 B1 and M1. I feel they are integral to this question, but I do not understand what role they play in the answer.
Aug
26
comment At the instant of release of an object from rest. Is the only force that can act its weight?
-1 If the math fails to explain the idealized physics then the math is wrong. In this case there is an incorrect application of the equations of motion.
Aug
26
comment At the instant of release of an object from rest. Is the only force that can act its weight?
Is the axis of rotation out of the plane through "A"?
Aug
26
comment At the instant of release of an object from rest. Is the only force that can act its weight?
When you do $\tau = I \alpha$ you have to express torques and mass moment of inertia about the center of mass and not the pivot axis.
Aug
25
comment Second order Non-exact ODE by integral factor
See math.stackexchange.com/help/notation for math formatting hints.
Aug
25
answered Index notation for inverse matrices
Aug
21
answered conic sections, ellipse
Aug
21
answered Geometric meaning of line equation in homogeneous coordinate
Aug
21
answered Solving these two equations simultaneously
Aug
21
comment Solving these two equations simultaneously
The general form of the second equation appears to be $\sqrt{y_c^2+(x-x_c)^2} + \sqrt{x_c^2+(y-y_c)^2} = R^2$. This has to be solved together with $\sqrt{x^2+y^2}=R$ when $x_c=-2$, $y_c=5$ and $R^2=98$ are given.
Aug
21
comment Line varieties in Projective Geometry!
Can you provide some context. Like how is the family of lines going to be used?
Aug
21
revised Circles - point of intersection of tangents
added 96 characters in body
Aug
21
comment Circles - point of intersection of tangents
Multiply the 3×3 by the 3 coordinates of the point. Like I state $L_B = U B$.
Aug
21
answered Circles - point of intersection of tangents
Aug
21
comment Spherical coordinate versor problem
Use your right hand, with the thumb and two digits to create an orthogonal coordinate system to visualize the cross product.
Aug
18
revised fit sine wave to data
added 2502 characters in body
Aug
18
answered fit sine wave to data
Aug
18
comment Direct formula for area of a triangle formed by three lines, given their equations in the cartesian plane.
Hint: The intersection point of two lines in homogeneous coordinates is $P=(a_1,b_1,c_1) \times (a_2,b_2,c_2)$ where $\times$ is the vector cross product. So three lines can be transformed two three vertices.