Question
If the total ages of A and B is 8 years more than the
total age of B and C. C is how many years younger than A?Solution
Let the age of A, B and C be x, y and z respectively. Then, according to question, => (x + y) – (y + z) = 8 => x + y – y - z = 8 => x - z = 8 Thus, C is 8 years younger than A.
- If cos θ = (4x² – 1)/(1 + 4x²) then find the value of sin q.

sin2 17˚ + sin2 19˚ + sin2 21˚ + sin2 23˚ + ……… + sin2 77˚ = ?
- If X = 15°, find the value of:
sin²(3X) + cos²(4X) - tan²(2X) If 7sin²θ + 3cos²θ = 4, then find the value of θ?
- In a triangle ABC, if 5∠A = 3∠B = 15∠C, then find the value of cosA + sin(C + 25 ° )
Find the exact value of cos120°
Find the value of the given trigonometric expression:
(sin 15°cos 75° + cos²15°) × sin 30° + (cos 60°tan 45°) × sec 60°
...[(sinx – 2sin 3 x)/(2cos 3 x – cosx)] 2  + 1, x ≠45 o , is equal to: