Question
What approximate value should come in the place of (?)
in the following questions? 713.92 ÷ 14.14 * 69.8 = ? * 20.74 ÷ 8.9Solution
ATQ,
714 ÷ 14 * 70 = ? * 21 ÷ 9
? = 51 * 70 * 9/21 = 1530
The minimum value of 45 sin2 θ + 28 cos2 θ is

Evaluate the following:
sin 60° × cos 30° + sin 30° × cos 60°
If 4sin² θ = 3(1+ cos θ), 0° < θ < 90°, then what is the value of (2tan θ + 4sinθ - secθ)?
- If 2cos²A + 3sin²A = 13/5, then find the value of (sec²A - 1)
- If sin (a + b) = (√3/2) and cos (a – b) = (√3/2), then find sin a.

sin2 17˚ + sin2 19˚ + sin2 21˚ + sin2 23˚ + ……… + sin2 77˚ = ?
If tan² 45°- cos² 60° x sin 45° cos 45° cot 30°, then find the value of 'x'.
If SecA + TanA = 2√2 + 9, then find the value of Sin A + Cos A.