IIT Level Trigonometry – 100 Questions (Set 4: 61–80)
61. sinθ + cosθ = a అయితే sin⁴θ + cos⁴θ = ?
Step: sinθcosθ = (a²−1)/2
= 1 − (a²−1)²/2
Answer = 1 − (a²−1)²/2
62. sinθcosθ = a అయితే sin⁶θ + cos⁶θ = ?
Answer = 1 − 3a²
63. sinθ + cosθ = √2 అయితే sin⁶θ + cos⁶θ = ?
Step: sinθcosθ = 1/2
= 1 − 3/4
Answer = 1/4
64. sinθcosθ = 1/4 అయితే sin⁶θ + cos⁶θ = ?
= 1 − 3(1/16)
Answer = 13/16
65. tanθ + cotθ = a అయితే sinθcosθ = ?
Answer = 1/a
66. sinθcosθ = a అయితే tanθ + cotθ = ?
Answer = 1/a
67. tanθ + cotθ = 5 అయితే tanθ = ?
x + 1/x = 5
x² − 5x + 1 = 0
Answer = (5 ± √21)/2
68. tanθ + cotθ = 6 అయితే tanθ = ?
x² − 6x + 1 = 0
Answer = 3 ± 2√2
69. sinθ + cosθ = a అయితే sin³θ + cos³θ = ?
Answer = a³ − (3a(a²−1))/2
70. sinθcosθ = a అయితే sin³θcos³θ = ?
Answer = a³
71. sinθ + cosθ = 1 అయితే sin³θ + cos³θ = ?
Step: sinθcosθ = 0
Answer = 1
72. sinθ + cosθ = 0 అయితే sin³θ + cos³θ = ?
Answer = 0
73. sinθ = 8/17 అయితే cosθ = ?
Answer = 15/17
74. cosθ = 7/25 అయితే sinθ = ?
Answer = 24/25
75. tanθ = 12/5 అయితే sinθ = ?
Answer = 12/13
76. tanθ = 5 అయితే cosθ = ?
Answer = 1/√26
77. sinθ + cosθ max?
Answer = √2
78. sinθcosθ max?
Answer = 1/2
79. tanθ + cotθ min?
Answer = 2
80. sinθ + cosθ = 2 అయితే possible?
Answer = Not possible