In Problems 77-88, use properties of the trigonometric functions to find the exact value of each expression. Do not use a calculator. 77. sin 40° + cos? 40° 78. sec? 18° – tan 18° \ 79. sin 80° csc 80° 80. tan 10° cot 10° sin 40° cos 20° 81. tan 40° 82. cot 20° 83. cos 400° - sec 40° 84. tan 200° - cot 20° cos 40° sin 20° 85. sin(-) se 2 37 COs 18 sin (- 20°) 87. sin 70° csc 86. sec + tan 200° 88. + tan(-70°) 18 cos 380° cos (-430°)
Trigonometric Identities
Trigonometry in mathematics deals with the right-angled triangle’s angles and sides. By trigonometric identities, we mean the identities we use whenever we need to express the various trigonometric functions in terms of an equation.
Inverse Trigonometric Functions
Inverse trigonometric functions are the inverse of normal trigonometric functions. Alternatively denoted as cyclometric or arcus functions, these inverse trigonometric functions exist to counter the basic trigonometric functions, such as sine (sin), cosine (cos), tangent (tan), cotangent (cot), secant (sec), and cosecant (cosec). When trigonometric ratios are calculated, the angular values can be calculated with the help of the inverse trigonometric functions.
In Problems 77–88, use properties of the trigonometric functions to find the exact value of each expression. Do not use a calculator.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps