Second degree

One method of finding the least equation for the simple second degree case is illustrated. Find a number r such that... 

The conduction of an impulse can be slowed or stopped at any point along the conduction system of the heart. Slowing of conduction is called first-degree block, block of some impulses is called second-degree block, and a block of all impulses is called third-degree block. 

Two quadratic equations in two variables can in general be solved only by numerical methods (see Numerical Analysis and Approximate Methods ). If one equation is of the first degree, the other of the second degree, a solution may be obtained by solving the first for one unknown. This result is substituted in the second equation and the resulting quadratic equation solved. 

To translate the axes to a new origin at (h, k), substitute for x and y in the original equation x + h and y + k. Translation of the axes can always be accomplished to eliminate the linear terms in the second-degree equation in two variables having no xy term. 

The type of cui ve determined by a specific equation of the second degree can also be easily determined by reducing it to a standard form by translation and/or rotation. In the case in which the equation has no xy term, the procedure is merely to complete the squares of the terms in X and y separately. 

To rotate the axes through an angle Ot, substitute forx the quantity X cos CL — y sin Ot and for y the quantity x sin Ci + y cos Ot. A rotation of the axes through Ot = V2 cot" (A — C)/B will eliminate the cross-producl term in the general second-degree equation. 

Second-Degree Least Squares with Five Points For five evenly spaced points x 2, X-, Xq, X, andi 2 (separated by distance / ) and their ordinates/ 2,/ i,/o,/i, and/2, assume a parabola is fit by least squares. Then the derivative at the center point is... 

The rate equations will be stated in these terms for a number of reactions. In all these cases, the integrands are ratios of second-degree equations. The moderately complex integrations are accomplished with the aid of a table of integrals, or by MATHEMATICA, or numerically when the constants are known. 

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Data not available Vapor (Gas) Irritant Characteristics Not pertinent Liquid or Solid Irritant Characteristics Fairly severe skin irritant. May cause pain and second-degree bums after a few minutes contact Odor Threshold Not pertinent. 

Late Toxicity Data not available Vapor (Gas) Irritant Characteristics Vapors are moderately irritating such that persoimel will not usually tolerate moderate or high concentrations liquid or Solid Irritant Characteristics Causes smarting of the skin and first-degree burns on short exposure may cause second-degree burns on long exposure Odor Threshold Data not available. 

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