Aptitude - Trigonometry
6.
sin2 25° + sin2 65° = ?
Answer
sin2 25° + sin2 65° = sin2 (90° − 65°) + sin2 65°
= cos2 65° + sin2 65° = 1
Answer :
Option AExplanation :
sin2 25° + sin2 65° = sin2 (90° − 65°) + sin2 65°
= cos2 65° + sin2 65° = 1
7.
cos 72° − sin 18° = ?
Answer
cos 72° − sin 18° = cos 72° − sin (90° − 72°)
= cos 72° − cos 72° = 0
Answer :
Option AExplanation :
cos 72° − sin 18° = cos 72° − sin (90° − 72°)
= cos 72° − cos 72° = 0
8.
If sin 42° = x, then cos 48° = ?
Answer
cos 48° = cos (90° − 42°) = sin 42° = x
Answer :
Option BExplanation :
cos 48° = cos (90° − 42°) = sin 42° = x
9.
The maximum value of (sin θ + cos θ) is :
Answer
(sin θ + cos θ) is maximum when θ = 45°
And, (sin 45° + cos 45°) = 1√2 + 1√2 = 2√2 = √2
Answer :
Option BExplanation :
(sin θ + cos θ) is maximum when θ = 45°
And, (sin 45° + cos 45°) = 1√2 + 1√2 = 2√2 = √2
= 108° Jump to page number :