What is the value of sin (B – C) cos (A – D) + sin (A – B) cos (C – D) + sin (C – A) cos (B – D)?

If 2y . cos θ - x . sin θ = 0 and 2x . sec θ - y . cosec θ = 3, what is the value of x² + 4y²?

Evaluate 3sin x – 4 sin³ x and figure out the correct answer from below option ?

The value of sec² 45˚ + 2 tan 135˚ is –

If x tan 60° + cos 45° = sec 45° then the value of x² + 1 is

If asinx +b cosx = c then find the value of acosx - bsinx =?

If θ is a positive acute angle and cos² θ + cos⁴θ = 1, then the value of tan²θ + tan⁴θ is?