 | Daniel Cresswell - 1816 - 352 σελίδες
...a (27-) = sin a sin b —cos a cos b (13.) .•. — cos (aJ-ft) = sin a sin b — cos a cos b, and cos (a + b) = cos a cos b — sin a sin b. And, in a similar manner, it may be shewn, that cos (a — b) = cos a cos b + sin a sin b. It is evident,... | |
 | 1836 - 366 σελίδες
...45°, shew that 2 sin ^ ± aj = \/l + cos 2a ± v/1 — cos 2a, PLANK TRIGONOMETRY. 1832 82. Prove that cos (A — B) = cos A . cos B + sin A . sin B; and find sin 3A in terms of sin A. QQ A * *2 + c2 — <*2 j . oo. Assuming cos A = ^ , deduce an expression... | |
 | Thomas Tate (mathematical master.) - 1848 - 284 σελίδες
...their sum or difference. . sin ( A + B) sin A . cos B + cos A . sin B tan(A + B)= ) , (- = — . --. v cos (A + B) cos A . cos B — sin A . sin B and dividing numerator and denominator by cos A . cos B, sin A sin B cos A "'"cos B tan A + tan B 1 tan... | |
 | Charles Davies - 1849 - 372 σελίδες
...it would still follow that cos (a + b) = CK'—I'L', or R cos (a + b) = cos a cos b—sin a sin h. And whatever be the values of the arcs a and b, it...formulas for the purpose of more convenient reference. sin a cos £ + sin b cos a sin ' . , ,, sin a cos b—sin b cos a ,_ > sin («—b)= g (2.). R _ cos... | |
 | Woolwich roy. military acad, Walter Ferrier Austin - 1880 - 190 σελίδες
...the same sign ? Find sin 120°, tan 60°, cos 135°. т> • » Prove sin A = —= (tan A)* 3. Prove cos (A -)- B) = cos A cos B — sin A sin B, and deduce from the formula the corresponding expressions for sin ( A -f- B), sin (A — B), and cos 2A.... | |
 | Isaac Todhunter - 1882 - 358 σελίδες
...+ B) = sin A cos Л + cos A sin B, then cos' (A + B) = (cos A cos B - sin A sin £)', and therefore cos (A + B) - ± (cos A cos B - sin A sin .B) ; and a little consideration shews that we must take the upper sign. 327. In Chapter viii. we have given... | |
 | Woolwich roy. military acad - 1884 - 148 σελίδες
...3. If (A + B) is an angle in the first quadrant, obtain by means of a geometrical figure the formula cos (A + B) = cos A cos B - sin A . sin B, and deduce from it the expression for cos (A — B). Find sec (A +B) in terms of sec A and sec B, and prove... | |
 | John Bascombe Lock - 1884 - 226 σελίδες
...{ - (180° + Л)}. Write down formulas including all angles which satisfy — (1) (2) 3. Prove that cos (A + B) = cos A cos B -sin A sin B, and deduce expressions for cos2Л, cos ЗA in terms of cos A. 5. Prove that (1) (2) (3) cos 20° + cos... | |
 | George William Usill - 1889 - 306 σελίδες
...sin B. Sin (A — B) = sin A. cos B — cos A. sin B. Cos (A + B) = cos A. cos B — sin A. sin B. Cos (A — B) = cos A. cos B + sin A. sin B. And from these, by addition and subtraction, we get Sine and Difference of Sines and Cosines.— Sin U.... | |
 | E. J. Brooksmith - 1889 - 356 σελίδες
...3. If (A + B) is an angle in the first quadrant, obtain by means of a geometrical figure the formula cos (A + B) =cos A cos B - sin A sin B, and deduce from it the expression for cos (A - B). Find sec (A + B] in terms of sec A and sec B, and prove... | |
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B) = cos A cos B — sin A sin B, (6a) cos (A — B) = cos A cos B + sin A sin B... 
