# Curve Sketching by H. M. Kenwood, C. Plumpton (auth.)

By H. M. Kenwood, C. Plumpton (auth.)

Similar algebra & trigonometry books

Homology of commutative rings

Unpublished MIT lecture notes

Rings, Extensions, and Cohomology

"Presenting the complaints of a convention held lately at Northwestern collage, Evanston, Illinois, at the get together of the retirement of famous mathematician Daniel Zelinsky, this novel reference offers updated insurance of subject matters in commutative and noncommutative ring extensions, specially these related to problems with separability, Galois idea, and cohomology.

Basic Category Theory

On the center of this brief advent to type idea is the assumption of a common estate, vital all through arithmetic. After an introductory bankruptcy giving the fundamental definitions, separate chapters clarify 3 ways of expressing common houses: through adjoint functors, representable functors, and bounds.

Extra info for Curve Sketching

Example text

1(a), (b), (c), (d), (e) and (f) respectively. cos x . 1 sin x The functions SIn x, cosec x = - . - , tan x = - - and cot x = - . , f(x) = - f( - x). e. f(x) = f( - x) . e. f(x) = f(x + 2nk) for all k E 71... e. f(x) = f(x + kn) for all k E Z. Sine waves The function f : x ..... a sin x + b cos x + c may be rewritten as f: x ..... R cos (x - a) + c. J(a 2 + b 2 ) , giving a unique value of a in the interval 0 ::::; a < 2n. 2 28 Curve sketching 2 (b) (a) cos x sin x x (d ) (c) cosec X Vi I I - 3,,/2 I I ,,/2 o 11\-1 I (e) ,,/2 sec x 2 1" I I I I !

By choosing k = 1 we are able to identify a unique value of a, called e, and for this function y = eX and :~ = e", The number e is irrational and its value is 2·71828 . . The function eX is called the exponential function and its graph is shown in Fig. 4(a). Transcendental curves 33 Working exercise On the same axes, sketch the graphs of y = 2\ y = eX and y = 3x • Note that all curves y = a" pass through the point (0, 1). The curve y = 2 X lies below that of y = eX for x > 0 and the curve y = 2X lies above y = eX for x < 0; the curve y = 3X lies above that of y = eX for x > 0 and below for x < O.

Are denoted by arcsin x, arctan x , etc. Working exercise Sketch the graphs of (a) y = SEC- 1 x and y = sec"! x, (b) y = COSEC- 1 x and y = cosec" x, (c) y = COT- 1 x and y = cot"! X. 3 Further parametric representations of curves Example 1 The ellipse b 2x 2 + a 2y2 = a 2b 2 (see Fig. 10(a), p. 19) is often expressed parametrically as x = a cos t , y = b sin t. Example 2 The hyperbola b 2x 2 - a 2y2 = a 2b 2 (see Fig. 1O(b), p. 19) is often expressed parametrically as x = a sec t, y = b tan t.