Cours de trigonométrie, conforme aux programmes de 1905 et contenant 300 exercices, par C. Fortin.

2I4 COURS DE TRIGONOMETRIE
Resoudre les equations suivantes:
I - tgx 2tgX
93. sin x - + g 94. cos x I + tg2X
I 'z tg+ X
95. tg x - tg2 = tg3. 96. sinl2( -- - cos2 7r- 3S).
97. I2COs2X = sin x. 98. sec x = sin x + 2 cos x.
99. tg 2x+cotg x = 8 cos2X. 100. 2 sin23 - sin26x = 2.
x x
101. sin 3x = sin7x-sin x. 102. 2 cos - — sin - 2.
2 2
103. sin2X+-cos2x=- 2 sin x. 104. 2 cos x+cos3x+cos5x =o.
105. 2 sin (x - + ) + cos (x- ) =32
(B. 're p. Dijon, I906).
106. sin2 (x + I5~) - sin ( - 15~) = 4.
107. 5 sin2x - 2 COS2X -- 3 sin x cos x - o.
108. sin2x cos x + 1 (I - cos x)3 + 1 sin2x (I -COS X).
109. cos 2x - cos 6x - sin 3x + sin 5x.
X 3x
110. sin x + sin 2X -- sin 3x= 4 cos - cos x cos -
2 2
111. 3 tgx - 2 cos X.
(B. ITe p. Poitiers, 1908).
112. cos x - /3 sin x - / 2.
(B. Ire p. Paris, I906).
113.
113. cos 2X t+ (cos x - sin x).
114. \/3 sln x + cos x 2.
115. sin 2 = cos (x +- h); o < h < 2
116. tg (x + a) (cos 2X - ) = sin 2X.
- 2 CO 2a
117. tg (a + x) tg (a-x I q- 2 cos2a